A. There has been some confusion about versions of Service Pack 6. To check which version of SP6 you are running run WINVER.EXE and if the text:
"Revised Service Pack 6a" appears under the copyright notice then you are running SP6a (notice it will still just say SP6 next to the build).
If the line is missing you are running the old SP6 and need to update your system with the patch available from http://download.microsoft.com/download/winntsp/Patch/6.0a/NT4/EN-US/Q246009i.EXE.
Click here to view image
A normal NT SP6 system
An updated SP6a system