OK, I'm a definite noob at this so, I need help... I'm trying to install the software for a ATI Radeon HD 2400 Pro 256 MB 64bit DDR2 into my computer. The operating system is Windows 2000 Professional. The screen pops up to install it, but when I click on install I get "this is not compatiable with your O.S." The box doesn't mention an O.S. requirement. Is there something else I can download that will make it install? Please help!