I'm having an issue with an Optiplex GX520, I am doing a repair install due to an 07b blue screen error, and during the XP Pro repair install, when windows wants some keyboard or mouse input, neither of them work, I have tried different KB's and mice,, only USB, no PS/2 ports on the machine. It looks like the devices aren't even getting power through the USB ports. I'm wondering if anyone here has run into this issue before.