This will be one of the few times you'll hear this, but Microsoft did too good a job creating XP.
Correction: They did a good job *FIXING* Windows XP.
If you recall the "instant infection" days where you couldn't install XP and run updates without getting infected. I had a people I helped over the phone who followed the procedure:
1. Install XP
2. Download the SP2 ISO
3. Burn the ISO to disk
4. Start over because they were compromised while downloading the ISO.
5. Install XP, then SP2 via CD.
If I was able to get them a CD I would, but many of my friends where college were in different states, or even different countries, and this was quicker than waiting for a CD in the mail.