Open task manager > Processes > Right-click a process > Set Affinity.
As far as I know XP supports up to 32 cores at once

. It's the RAM cap that screws it over though.
But yeah, I got my computer when XP was almost brand new, 2.08GHz 32-bit single-core piece of crap with only 1GB RAM. I tried putting Vista on it once, the sidebar crashed within 8 seconds of booting up the first time, and the Aero theme went about a half hour after that. Plus to my knowladge, Vista is the ONLY operating system that has "incompatibility issues" with certain monitors. It's almost obviously a scam just for MS to get more money off of companies like Acer and HP
R0b0t1, mind explaining those legal issues?
Also, Ubuntu is ftw. If you're using Vista because it looks pretty, you should be using Linux with the Beryl theme. If you like Vista because of it "security policy" (meaning no one's allowed to do anything), get Linux

. I only keep my XP around because of SCAR, FL Studio, and Photoshop.
Edit: The XBox 360 OS also has certain "compatibility issues" with certain companies too