Sorry for the late response. I set the security permissions to allow everyone access to the drive. This solved half my problem, being that I can now read/write to the HDD with two computers, one running Vista Premium and the other running Vista Basic. When I try on both my XP Pro and XP MCE computers, I still get the error message. Also, when I go into the HDD properties, it lists the file system as RAW, with 0mb capacity. Also, the HDD is not USB powered. I Hope this helped.