It shows up in my BIOS as a hard drive. In XP64 it shows as Floppy drive letter A and most importantly, the drive will not format. Since it shows as a floppy drive, I can't format it in XP64. But if I try to do it while doing a new Windows install, it goes through the motions. The drive trys to format and gets to 100%. But afterward it says that the drive could not be formatted and that there may be a problem with it. I think the compatibility issue is causing this because I have another Western Digital drive (different model) that I bought at the same time as this one, and that one works perfectly. It's just this model that seems to have an issue with P35 boards. And if it doesn't work for me and I paid money for it, thats more then a legitamate reason to RMA it.