Your "info" is way off, durabox.
Unless you are trying to run some really old games, win7 is the way to go. XP is still a good OS, but it is well past its prime. I haven't hit a game that won't run on 7, even if I do have to tweak it a bit (my fault, not 7's).
Errors? 7 is the most bug-free OS Microsoft has ever released.

Even the betas were solid.
If you are staying on an old rig, stay with XP. If you arebuilding/buying a new one, go 7. Nice and simple.