Troubleshooting the PXE Service Point in Configuration Manager 2007

This is a general guide on properly setting up and troubleshooting the System Center Configuration Manager 2007 (ConfigMgr 2007) PXE Service Point.
Common errors that are seen at the PXE boot screen when the PXE Service Point is either not configured properly or experiencing problems are the following:
PXE-E53: No boot filename received
PXE-T01: File not found
PXE-E3B: TFTP Error - File not Found
PXE-E55 Proxy DHCP Service did not reply to request on port 4011
PXE-T04: Access Violation
PXE-E36: Error Received from TFTP Server 
PXE-M-F Exiting PXE Rom




To resolve these issue and to prevent them from occurring in the first place, follow the guide below  This guide is broken down to the following sections.

Setting Up IP Helpers

If the DHCP server, the client PC, and the ConfigMgr 2007 server are running WDS and the PXE Service Point are all on the same subnet or vlan, please proceed to the section "How To Properly Install and Set Up The PXE Service Point". Otherwise, if either the DHCP server, the client PC or the ConfigMgr 2007 server is running WDS and the PXE Service Point are on separate subnets or vlans, which is usually the case in most environments, the first step to take before trying to install and configure the PXE Service Point and WDS is to set up IP Helpers on the routers. How to do this varies depending on the router hardware manufacturer but the general overview is outlined at the below link:

Configuring Your Router to Forward Broadcasts http://technet.microsoft.com/en-us/library/cc732351(WS.10).aspx#Updating

For further information on how to properly configure IP Helpers on the routers, please contact the hardware manufacturer of the router.

IP Helpers are necessary because the PXE request generated by the client PC is a broadcast that does not travel outside of the local subnet or vlan. It only stays within the local subnet or vlan. If the DHCP server and/or the WDS/PXE Service Point server are not on the subnet or vlan as the client PC, they will not see or hear the PXE request broadcast from the client PC and therefore will not respond to the PXE request. To have the PXE request broadcast transverse between subnets or vlans, the PXE request broadcast needs to be forwarded by the router to the DHCP and WDS/PXE Service Point servers so that they can properly respond to the client PC's PXE request.

An alternative to using IP Helpers is setting DHCP Options on the DHCP server, specifically DHCP Options 60 (PXE Client), 66 (Boot Server Host Name), and 67 (Bootfile Name). However, DHCP Options can be problematic and may not work reliably or consistently. Furthermore the use of DHCP Options to control PXE requests is not supported by Microsoft. Therefore the only recommended and supported method of PXE booting client PCs that are on a different subnet than the DHCP or WDS/PXE Service Point servers is the use of IP Helpers.

For additional information regarding DHCP Options not being recommended or supported please see the below articles:

Using DHCP Options 60, 66, and 67 http://technet.microsoft.com/en-us/library/cc732351(WS.10).aspx#Using

PXE clients computers do not start when you configure the Dynamic Host Configuration Protocol server to use options 60, 66, 67 http://support.microsoft.com/kb/259670

The only exception where a DHCP Option needs to be used is when DHCP and WDS reside on the same server. In this instance, DHCP Option 60, and only DHCP Option 60, needs to be set. DHCP Options 66 and 67 should still NOT be set in this scenario. For more information, please see the section "Windows Deployment Services (WDS) and DHCP" in the following article:

Planning for PXE Initiated Operating System Deployments http://technet.microsoft.com/en-us/library/bb680753.aspx

It is IMPERATIVE that before continuing that it has been verified that the routers have IP Helpers configured AND that the DHCP server does NOT have DHCP Options 60, 66, or 67 configured. Not meeting both of these criteria will cause the PXE Service Point not to work correctly. When checking DHCP options, make sure to check options at both the server and scope levels.

In certain instances, configuring DHCP Options 60, 66, and 67 may make it appear that the PXE boot process is proceeding further along than before these options were configured, but in reality it just proceeds further down an incorrect path, ends up giving different error messages, and ends up failing.

How To Properly Install And Set Up A New Instance Of WDS And A PXE Service Point

The following section lists the step to ensure that that a NEW instance of the PXE Service Point is set up and configured properly. If Windows Deployment Services (WDS) and/or the PXE Service Point has been previously installed, even if it never worked, follow the instructions under the section "Reinstalling WDS And The PXE Service Point" instead:

1. If needed, make sure that IP Helpers have been configured. Additionally, make sure that DHCP Options 60, 66, 67 have NOT been configured. See the section "Setting Up IP Helpers" for additional information.

2. Install, but DO NOT configure, Windows Deployment Services (WDS) on the server that will host the PXE Service Point.

• If using Windows Server 2003, WDS is installed via the Add/Remove Windows Components in theAdd/Remove Control Panel.
• If using Windows Server 2008 or newer, WDS is installed via Roles in Server Manager. When installing in Windows Server 2008 or newer, make sure that both the Deployment Server and Transport Server are installed.

3. If prompted to do so after WDS has finished installing, reboot the server.

4. Once the server has restarted, DO NOT try to manually configure or start the WDS service.

5. In the ConfigMgr 2007 Admin Console, navigate to "Site Management" --> <Site_Code> --> "Site Settings" --> "Site Systems".

6. If the server where the PXE Service Point is going to be installed already exists under "Site Systems", right click on the server and choose "New Roles".  Otherwise right click on "Site Systems" and choose "New" --> "Server".

7. In the "General" page of the wizard, make sure that the NETBOIS and FQDN name of the server are correct and then click on the "Next >" button.

8. In the "System Role Selection" of the wizard, check "PXE service point" and then click on the "Next >" button.

9. Review the "PXE Service Point Configuration" dialog windows and then click on the "Yes" button.

10. In the "PXE - General" window, configure the appropriate options as desired and then click on the "Next >" button.

11. In the "PXE - Database" window, change any options as needed. In most cases, leave settings at their default in this window. Click on the "Next >" button.

12. Click on the "Next >" button and then on the "Close" button.

13. On the server where the PXE Service Point is being installed, navigate to the ConfigMgr 2007 site server log location using Windows Explorer. Usually the log location will be under one of the following paths:

• 32bit servers <drive_where_ConfigMgr_is_installed>\Program Files\Microsoft Configuration Manger

• 64bit servers <drive_where_ConfigMgr_is_installed>\Program Files (x86)\Microsoft Configuration Manger\Logs

• 32bit or 64bit servers <drive_where_ConfigMgr_is_installed>\SMS

14. Once the log directory has been located in Step 13, open the log file PXESetup.log using SMS Trace/Trace32.exe.  Monitor this log and verify that the PXE Service Point installed correctly. It may take a few minutes for the installation to start and finish successfully. If this is the first time the PXE Service Point is being installed on the server, it may take a few minutes for the PXESetup.log to appear and be created.

Once installed correctly, the last lines in the log should be "pxe.msi exited with return code: 0" and "Installation was successful." Verify that the line is for the current date and time frame.

In some circumstances, the last lines will read "pxe.msi exited with return code: 3010" and "Installation was successful, but a reboot is required." If this is the case, make sure to reboot the server before continuing.

Do NOT proceed until confirmation has been received in the PXESetup.log that installation has been successful.

15. In the ConfigMgr 2007 Admin Console, navigate to "Computer Management" --> "Operating System Deployment" --> "Boot Images".

16. If BOTH the x64 and x86 Boot Images are not already on any standard Distribution Point (DP), make sure to put both Boot Images on at least one standard DP. Monitor the "Package Status" node and ensure that both the x64 and x86 Boot Images properly install on the standard DP.

17. Place BOTH the x64 and x86 Boot Images on the SMSPXEIMAGES$ DP on the server where the PXE Service Point was created. Monitor the "Package Status" node and ensure that both the x64 and x86 Boot Images properly install on the SMSPXEIMAGES$ DP.

18. Once the Boot Images have installed on the SMSPXEIMAGES$ DP, open the Services console on the PXE Service Point server and ensure that the Windows Deployment Services Server service has started. Additionally make sure that the RemoteInstall folder has been created on the root level of the one of the drives of the server.

19. In the ConfigMgr 2007 Admin Console, navigate to "Computer Management" --> "Operating System Deployment" --> "Task Sequences". Right click on each Task Sequence that will be deployed via PXE and choose "Properties". Click on the "Advanced" tab and ensure that the option "Use a boot image:" is checked and that an appropriate boot image for that Task Sequence is selected.

20. In the ConfigMgr 2007 Admin Console, navigate to "Computer Management" --> "Software Distribution --> "Advertisements". Right click on each Advertisement for Task Sequences that will be deployed via PXE and choose "Properties". Under the "General" tab make sure that the option "Make this task sequence available to boot media and PXE" is checked.

Notes:

1. When the PXE Service Point is installed, it will automatically configure WDS and create the RemoteInstall folder. Once configured, the PXE Service Point installation will then automatically start the WDS service. For this reason, manual configuration of WDS in the Windows Deployment Services console is NOT necessary and should not be performed.

The only exception to this rule is when DHCP and WDS reside on the same server. In these cases, consult the section "Windows Deployment Services (WDS) and DHCP" in the following article:

Planning for PXE Initiated Operating System Deployments http://technet.microsoft.com/en-us/library/bb680753.aspx

2. Once the PXE Service Point has configured and started WDS, the Windows Deployment Services console will still show a yellow exclamation mark and display the message "Windows Deployment Services is not configured". This is normal and does not indicate a problem. No action or configuration should be taken in theWindows Deployment Services console.

3. Regardless of the architecture of the Windows OS being deployed, it is IMPERATIVE that BOTH the x86 and x64 Boot Image are on BOTH a standard DP and the SMSPXEIMAGES$ DP. Make sure to verify that this has been done.

4. Do NOT place any other types of packages other than Boot Images in the SMSPXEIMAGES$ DP. Placing any other type of packages in the SMSPXEIMAGES$ DP, especially OS images, may cause WDS not to work correctly.

Reinstalling WDS And The PXE Service Point

In certain scenarios, especially ones where WDS and the PXE Service Point were initially installed or configured incorrectly, the best course of action is to uninstall the PXE Service Point and WDS, delete all previous configurations, and then reinstall:

1. In the ConfigMgr 2007 Admin Console, navigate to "Computer Management" --> "Operating System Deployment" --> "Boot Images".

2. Under each Boot Image, click on the "Distribution Points" node. On the right hand panel, right click on the "\\<Server_Name>\SMSPXEIMAGES$" DP and then choose "Delete" (where <Server_Name> is the name of the server where the PXE Service Point and WDS is being reinstalled). If the Boot Image is installed on the standard DP, it is NOT necessary to also delete the Boot Image from the standard DP.

3. Under each Boot Image that was deleted, monitor the "Package Status" node under the Boot Image to ensure that the Boot Image is removed from the SMSPXEIMAGES$ DP. To verify, check the "Package Status" node under the first "Package Status" node. Once the Boot Image has been successfully deleted from the DP, "Source Version", "Targeted", and "Installed" will all be 0.

4. Make sure that no other packages are on the SMSPXEIMAGES$ DP. To check if there are any other packages on the SMSPXEIMAGES$ DP, on the server where the PXE Service Point is being uninstalled, navigate to the folder RemoteInstall\SMSImages\SMSPKG. The RemoteInstall folder will be on the root level of one of the drives of the server. If the folder is empty, all packages have been removed. If the folder contains subfolders, there are additional packages on the SMSPXEIMAGES$ DP that need to be removed:

a. To determine which packages are on the DP, copy down the folder names. The folder names correspond to the Package ID of the package that is on the DP.
b. In the ConfigMgr 2007 Admin Console, navigate to "System Status" --> "Package Status". On the right hand panel all of the packages in the environment will be listed. On the far right last column the Package ID will be listed. Match up the Package ID obtained in Step 1
with the Package Name.
c. Based on the Package Name obtained in the Step 2, locate the package under one of the following nodes in the ConfigMgr 2007 console:

•  
  • "Computer Management" --> "Software Distribution" --> "Packages"
  • "Computer Management" --> "Operating System Deployment" --> "Operating System Images"
  • "Computer Management" --> "Operating System Deployment" --> "Operating System Install Packages"
  • "Computer Management" --> "Operating System Deployment" --> "Driver Packages"
  • "Computer Management" --> "Software Updates" --> "Deployment Packages"

d. Under each package, click on the "Distribution Points" node. On the right hand panel, right click on the "\\<Server_Name>\SMSPXEIMAGES$" DP and then choose "Delete" (where <Server_Name> is the name of the server where the PXE Service Point and WDS is being reinstalled).
e. Under each package that was deleted, monitor the "Package Status" node under the package to ensure that the package is removed from the SMSPXEIMAGES$ DP. To verify, check the "Package Status" node under the first "Package Status" node. Once the package has been successfully deleted from the DP, "Source Version", "Targeted", and "Installed" will all be 0.
f. Once all of the packages have been deleted, check the RemoteInstall\SMSImages\SMSPKGfolder on the server where the PXE Service Point is being uninstalled and and ensure that it is empty.

5. On the server where the PXE Service Point and WDS are being deinstalled, open the Services console. Locate the "Windows Deployment Services Server" service, right click on it, and select "Stop". If the service is already stopped, proceed to Step 6.

6. In the ConfigMgr 2007 Admin Console, navigate to "Site Management" --> <Site_Code> --> "Site Settings" --> "Site Systems".

7. Under "Site Systems", click on the server where the PXE Service Point is being uninstalled.  On the right hand panel right click on "ConfigMgr PXE service point" and choose "Delete". In the "Confirm Delete" dialog box, click on the "Yes" button.

8. On the server where the PXE Service Point is being uninstalled, navigate to the ConfigMgr 2007 site server log location using Windows Explorer. Usually the log location will be under one of the following paths:

• 32bit servers <drive_where_ConfigMgr_is_installed>\Program Files\Microsoft Configuration Manger
• 64bit servers <drive_where_ConfigMgr_is_installed>\Program Files (x86)\Microsoft Configuration Manger\Logs
• 32bit or 64bit servers <drive_where_ConfigMgr_is_installed>\SMS

9. Once the log directory has been located in Step 8, open the log file PXESetup.log using SMS Trace/Trace32.exe. Monitor this log and verify that the PXE Service Point uninstalled correctly. It may take a few minutes for the deinstallation to start and finish successfully. Once uninstalled correctly, the last line in the log should be "SMSPXE deinstall exited with return code 0", "Deinstallation was successful.", and "Removing PXE Registry." Verify that the lines are for the current date and time frame.

If the deinstall of the PXE Service Point never kicks off, check the sitecomp.log on the parent site server to determine why it was not able to start the deinstall. In most cases it is due to file in use issues, which usually can be resolved by stopping the WDS service (Step 5).

Do NOT proceed until confirmation has been received in the PXESetup.log that deinstallation has been successful.

10. Uninstall Windows Deployment Services (WDS) on the server:

a. If using Windows Server 2003, WDS is uninstalled via the Add/Remove Windows Componentsin the Add/Remove Control Panel.
b. If using Windows Server 2008 or newer, WDS is uninstalled via Roles in Server Manager.

11. Reboot the server where WDS and the PXE Service Point were just deinstalled.

12. Once the server reboot completes and the server comes back up, locate the RemoteInstall folder on the root level of each of the drives of the server. If it exists on the drive, rename the RemoteInstall folder (i.e.RemoteInstallOld). On most servers, only one of the drives will have a RemoteInstall folder. However if multiple instances of the RemoteInstall folder exist, make sure to rename each instance.

If when renaming the RemoteInstall folder you receive one of the below messages:

Windows Server 2008/Windows Server 2008 R2 This folder is shared with other people
If you rename this folder, it will no longer be shared.
Folder: <drive_letter>\RemoteInstall
Share Name: REMINST 
or

Windows Server 2003 You are sharing <drive_letter>:\RemoteInstall\SMSIMAGES as SMSPKEIMAGES$. The folder will not be shared after you move or rename it. Are you sure you want to continue? 
go ahead and make sure to click on either the "Continue" or "Yes" button.

13. On the server where WDS and the PXE Service Point were uninstalled, delete the folders BootImages andPXEBootFiles under %systemroot%\Temp (usually C:\Windows\Temp). It may be necessary to take ownership of the folders and their subfolders to successfully delete the folders. In some circumstances, it may be necessary to also navigate down the folder hierarchy and take ownership from the bottom up.

14. Reinstall WDS and the PXE Service Point using the instructions in the section "How To Properly Install and Set Up A New Instance of A PXE Service Point".

Testing The PXE Service Point

Once WDS and the PXE Service Point have been installed and configured, test the PXE Service point to see if it is working. Take the following measures to ensure the best testing environment:

1. To eliminate problems with Unknown Computer Support, advertise the Task Sequence to a collection that has known existing clients. If necessary, use the Computer Association node to manually create a client record. For best results, create the record based on the SMBIOS GUID (System UUID) of the PC and NOT the MAC address.

2. To eliminate certain issues that can occur with mandatory assignments, do not add a mandatory assignment to the advertisement of the Task Sequences. Instead the Task Sequence advertisement should be completely optional.

3. Verify the properties of the advertisement and ensure that under the "General" tab the option "Make this task sequence available to boot media and PXE" is checked.

4. Verify the properties of the Task Sequence and ensure that under the "Advanced" tab the option "Use a boot image:" is checked and that a boot image assigned under this option.

5. Refer to the below two KB articles regarding the SMS PXE Cache:

Client machines may fail to boot into PXE if System Center Configuration Manager Service Pack 2 has been applied http://support.microsoft.com/kb/2019640
Operating system deployment fails in a System Center Configuration Manager 2007 SP1 environment if you deploy a different operating system to a client within one hour of a previous deployment http://support.microsoft.com/kb/969113
During testing is suggested to set the value of the CacheExpire key to 60 (60 seconds = 1 minute). This will minimize PXE booting issues being caused by the SMS PXE cache. The default of the CacheExpire key is either 0 or 3600, both which are 3600 seconds (1 hour). After testing is complete, the value of this registry setting will need to be determined based on environmental conditions.

Monitoring And Troubleshooting The PXE Boot

The single greatest troubleshooting tool in figuring out why a PXE boot is not working on a client PC is monitoring the SMSPXE.log. The log should be monitored live with SMS Trace/Trace32.exe while a PXE boot is attempted on the client PC. When monitoring the SMSPXE.log, the log should show in real time exactly what is occurring.

1. While attempting a PXE boot on a client PC, perform a live monitor of the log SMSPXE.log with SMS Trace/Trace32.exe. The SMSPXE.log log can be found under the MP/client logs of the ConfigMgr site server hosting the PXE Service Point. The location of the MP/client log files is usually under one of the following paths:

32bit servers <drive_where_ConfigMgr_is_installed>\Program Files\SMS_CCM\Log or
%systemroot%\System32\CCM\Logs (usually C:\Windows\System32\CCM\Logs)

64bit servers <drive_where_ConfigMgr_is_installed>\Program Files (x86)\SMS\CCM\Log or
%systemroot%\SysWow64\CCM\Logs (usually C:\Windows\System32\CCM\Logs)

32bit or 64bit servers <drive_where_ConfigMgr_is_installed>\SMS_CCM\Log

2. Monitoring the SMSPXE.log should show the activity in the log when the actual PXE request is occurring. If no activity is occurring, this is usually indicative of one of the following problems:

• The WDS service has not started or is not running
• The PC is on a separate subnet or vlan from the WDS and DHCP servers and IP Helpers have not been properly set up
• DHCP Options 60, 66, or 67 have been configured

3. Enabling debug logging on the SMSPXE.log could assist in troubleshooting why a PC is not PXE booting by giving additional information about the PXE request.  To enable debug logging on the PXE Service Point server for the SMSPXE.log , modify the following registry key on the server to a string value of "True" (without the quotes):

32bit Windows Server HKLM\SOFTWARE\Microsoft\CCM\Logging\DebugLogging!Enabled 
64bit Windows Server HKLM\SOFTWARE\Wow6432Node\Microsoft\CCM\Logging\DebugLogging!Enabled 
Once the change has been made, restart the server for the changes to take effect.

4. Lines in the SMSPXE.log that show PXE requests that contain all Fs as the MAC address similar to the below line can be ignored:

MAC=FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF SMBIOS GUID=<SMBIOS_GUID> > Received DHCP Request smspxe
Executing LookupDevice(<SMBIOS_GUID>, FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF) smspxe
CDatabaseProxy :: LookupDevice succeeded: 0 0 0 0 smspxe
MAC=FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF SMBIOS GUI=<SMBIOS_GUID > > Device not found in the database. smspx
MAC=FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF SMBIOS GUID=<SMBIOS_GUID > New client request. RequestID=<Request_ID>. smspxe 
These PXE "requests" are just the server doing a self check on itself to ensure the PXE Service Point is up and responding.

5. The error in the SMSPXE.log:

Failed to read PXE settings.
The system cannot find the file specified. (Error: 80070002; Source: Windows) smspxe 
can be ignored and is not relevant. It does not indicate that there are any problems.

6. If the following messages appear at the PXE boot screen:

TFTP Download: smsboot\x86\abortpxe.com
PXE Boot aborted. Booting to next device... 
or

TFTP Download: smsboot\x64\abortpxe.com
PXE Boot aborted. Booting to next device... 
it is indicative that the PXE Service Point and WDS are installed and configured correctly and working as expected. The above error messages occur when an advertised Task Sequence is not found for the PC that is being PXE booted. The PXE Service Point then responds appropriately and sends a PXE abort.

The problem is usually associated with how the Task Sequence is advertised and targeted to the PC. Usually in these scenarios the following message will show up in the SMSPXE.log for the PXE request:

ProcessDatabaseReply: No Advertisement found in Db for device smspxe

7. The SMSPXEIMAGES$ DP is actually a share pointing to the SMSIMAGES folder within the RemoteInstallfolder. ConfigMgr places the Boot Images in this share so that the Boot Images are available to WDS for PXE booting. In total there should only be four folders within the RemoteInstall folder as follows:

SMSBoot
SMSIMAGES
SMSTemp
Stores 
If additional folders exist in the RemoteInstall folder, such as:

Boot
Images
Mgmt
Templates
Tmp
WdsClientUnattend

this is an indication that WDS has been manually configured at some point. The best course of action at this point is to reset the installation of WDS by reinstalling the PXE Service Point and WDS as described in the section "Reinstalling WDS And The PXE Service Point".

8. ConfigMgr uses the Boot Images in the RemoteInstall\SMSIMAGES folder to extract Boot Files from the Boot Images. In addition to the Boot Images, these Boot Files are also needed by WDS to successfully complete a PXE boot. These Boot Files are placed in the SMSBoot folder under the RemoteInstall folder. The process of extracting the Boot Files can be seen by monitoring the SMSPXE.log while the WDS service is restarted. If errors appear in the log during this process (besides the error described in Step 5 above), the best course of action is to reinstall the PXE Service Point and WDS as described in the section "Reinstalling WDS And The PXE Service Point".

9. The RemoteInstall\SMSIMAGES folder will contain a subfolder called SMSPKG, which will then contain subfolders for each Boot Image that has been added to the SMSPXEIMAGES$ DP. Each subfolder under theSMSPKG folder will have the name of the Package ID of the Boot Image.

If any subfolder exists under SMSPKG that is not the Package ID of a Boot Image, they should be removed from the SMSPXEIMAGES$ DP via the ConfigMgr 2007 Admin console. Only Boot Images should be added to theSMSPXEIMAGES$ DP. No other type of packages should be added to the SMSPXEIMAGES$ DP. This is especially true with Operating System Image Package or an Operating System Install Package (Windows OS source files). Having an Operating System Image Package or an Operating System Install Package under theSMSPXEIMAGES$ DP will cause issues with WDS.

Instructions on how to remove additional packages from the SMSPXEIMAGES$ DP are provide above in Step 4 under the section "Reinstalling WDS And The PXE Service Point". However make sure not to remove the Boot Images as outlined in the instructions.

10. The RemoteInstall\SMSBoot folder should have three folders listed under it, one for each architecture type -ia64, x64, and x86. The ia64 folder will be empty since ia64 is not an officially supported platform for ConfigMgr 2007 OSD. However, both the x64 and x86 folders should have the following files in them:

abortpxe.com
bootmgfw.efi (x64 only)
bootmgr.exe
pxeboot.com
pxeboot.n12
wdsnbp.com

If the folders are missing, empty, or missing files, then BOTH the x64 and x86 Boot Images may not have been placed in the SMSPXEIMAGES$ DP. If both the x64 and x86 Boot Images have been placed on theSMSPXEIMAGES$ DP and the folders still do not exist, are empty, or are missing files, then there may be another problem occurring. The best course of action is to reinstall the PXE Service Point and WDS as described in the section "Reinstalling WDS And The PXE Service Point".

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      The Configuration Manager Support Team Blog