Most old software gets remaindered to the bargain bins. Not Windows XP, however. In June, Dell wangled a deal with Microsoft to let it install the older operating system for customers who didn't want Vista. In June, the companies charged $50 extra. According to this order page, XP now costs an extra $99 — on top of the cost of Windows Vista, which is baked into the basic price for the computer. Here's the full order page: