Thanks. I just want to wipe the drive to make sure I get rid of any sensitive data. Would installing ubuntu really overwrite all of the data on the drive?
No, the OS will only overwrite a portion of the drive, but as you install new software and create data files they will overwrite portions of the drive that previously had files on it. Anyhow, a simple format should suffice. If I were throwing the drive in the trash or giving it to a friend, then I'd wipe it with DBAN or some other utility.