troubleshoot PXE problem

Check the SMSTS.log for following:

Network Access Account Not Set
Resolution: Go into the Client Policy in SCCM and set a Network Access Account. It sometimes "disappears" even after everything has been working fine.
http://www.myitforum.com/forums/m_177370/mpage_1/key_/tm.htm#177370

PXE CERT Not Set
Resolution: Check the PXE Certificate in the SCCM console. Verify that the Root CA is trusted. Alternatively, reset the expiration date.
http://www.myitforum.com/forums/m_177312/mpage_1/key_/tm.htm#177312

GetHostByName Failed
Resolution: Ensure the FQDN is properly set.
http://www.myitforum.com/forums/m_177318/mpage_1/key_/tm.htm#177318