If you are using a Dlink wireless card WDA-1320 and others, make sure
you download and install the latest drivers for XP - Ver:1.30 for XP
and Vista first.

SP3 update causes a BSOD on first reboot and various errors on
subsequent boots if you have older drivers.

WZCSLDR2.exe - Entry point not found
AirGCFG.exe - Entry point not found
Rsop errors
A provider, Rsop Planning Mode Provider, has been registered in the
WMI namespace, root\RSOP, but did not specify the HostingModel
property.

Hope this helps somebody.
Roy