Xeon FAQ

[IronBits]

Found a most excellent information page
http://forums.2cpu.com/showthread.php?s=&threadid=34330

What version of Windows will work with HT?

Windows XP (Home and Pro) can tell the difference between a physical CPU and a virtual (HT) CPU.

With XP Home, you can have 1 physical CPU, or 2 with HT.

With XP Pro, you can have 2 physical CPUs, or 4 with HT.

Windows 2000 (All versions), cannot tell the difference between a physical and virtual CPU.

With Windows 2K Pro, you can have 2 Physical CPU's W/O HT, or 1 Physical CPU WITH HT. Either way it's counted as 2 CPU's.

Windows XP will only count the physical CPU's for licensing.

Windows 2000 will count ALL of the CPU's for licensing

[Fozzie]

with the triple paste.

[IronBits]

wtf? Looks at original linkage. they did it... it was late.
good catch

[Jeff]

I can verify that Windows 2000 Advanced Server seems to run fine with a couple of Xeons w/HT. I've read that AS doesn't handle HT correctly but I haven't noticed any difference between my XP and AS rigs(and I use my AS rig daily).