Verified answer

Yes it is. Win XP MCE is based on Win XP Professional (it's basically the same thing with added different user interface), which does support multicore processors.

Yes It will run fine.

But if you get Window XP Media Center Edition 2005 64bit it will a lot faster.

im a impressive fan of the middle 2 quad and that i love the final performance of it so i might want to bypass with HP pc XW4600 Intel middle 2 Quad Q9550 Processor / 2.80 3 GHz, 12 MB L2 cache, 1333 MHz FSB

while Gary is correct the 64bit may not run alot of your programs so be aware of that