CompUSA has the Windows XP Home Edition Upgrade with SP2 by Microsoft for only $49.99 after rebate.

Pricegrabber Price : $78.49 ~ $139.59 Shipped

1. CompUSA Price : $99.99
2. Choose to pickup in-stores to save on shipping.
3. Rebate Price : -$50.00
Final Price : $49.99 After Rebate