This is the OEM disks, not full retail.
OEM has a limited license. You are only allowed to install it on one computer, and one computer alone. You can't move it to a different system.
The full retail one, you can move it to another system, but it also costs more.
PC manufactures use OEM installs, not full retail.
I hate Vista. You have to pay like 60 bucks more or something to actually get a version thats not sh!t.
There so obsessed now with "verifying" that you have a genuine XP version, only less than 2/50 are actually pirated version now, they'll actually have to worry about it when this happens.