Yes, XP will work just fine. I have had XP running on my 1.83 GHz Mini through VM, Parallels, and Boot-Camping-it, and I thought that all three worked well for the basics (Internet and I got a free copy of Office 2007 Ultimate that I wanted to use on it). The 2009 Mini has the new graphics, a faster processor and FSB, and if you're maxing out the DDR3 memory, it should be "blazing"!