It work on my PC, and i wait the RTM of Longhorn to upgrade my computer. I have AMD Athlon XP 1,2 Ghz ATI Radeon 9200 SERIES 256 Mo 512 Mo RAM HDD : 80 Go (30 Go for Windows XP Professionnel SP2, 40 Go for my personal data 10 Go for test Longhorn 4074) I advise all to no upgrade XP with a beta of longhorn because i think they cause somes problems .... MEstk