I hooked up a USB drive to my DVR to epxand my recording time. The DVR reformated the USB hard drive. It turns out this drive is not compatable with the DVR. I would like to use the drive, as it is brand new, so I am trying to hook it up to my XP system. the drive shows up in the Device Manager as disk 4, but it does not show up in Disk Management. I also ran the "diskpart" utility. It does not show up in the "list disk", but I can "select disk 4". But when I do select it, I can't do anything to it. Any suggestions on how I can reformat this disk to use on an XP system?