Completely and utterly FALSE information you have been given . I have several THOUSANT GX380 , GX760, and GX980 desktops that run windows 7 just fine. I also have XP on the same machines. the GX280 in particular doesn't have any drivers for windows 7 , the gx260 and 70 , yes they do in fact . just not the 280.
saint19 is not posting completely false information, he just should have been more specific. Earlier GX series systems like the GX260, 270 and 280 have no official driver support from Dell for Windows Vista or Windows 7. Newer GX series systems though, are supported by Dell on Vista and 7.
And next time, please do not necro-post.