I see a new computer in my future

My home desktop is still shutting off. I tried blowing all the dust and junk out -- but it didn't help. Or if it did, only in making the sudden shut-off take a bit longer than it otherwise might. So, I see a new computer. I think I'll go shopping early next week. Not sure exactly what I want, but it won't be hard to be better -- even the bottom end is better, and mine was only 3 years old. (Though, it was bottom end at that time, too.) I wonder if anyone will sell me a machine with XP as the base install, rather than (*shudder*) Vista.