When trying to PXE boot into an SCCM 2007 OSD, you get a pending request ID error on the client. Assuming you have cleared any pending ID requests in SCCM (Right click the computer object and Clear Last PXE Advertisement), you may have one of the following issues:
- You could have the MAC address wrong in the computer object in SCCM 2007
- SCCM 2007 could be lying to you and you need to restart the Windows Deployment Services Server service on the SCCM server