I have two Western Digital WD400 hard drives that I pulled from an older computer in my house. I know both work. I have used them when plugged into my USB adapter on my new computer. I have recently tried to format both in XP to delete all the old stuff on them and XP cannot seem to format them. It quits. However, when I do a raw format under the western digital program, it works. This however does not make it XP ready. The drives are 40gb, plugged into my USB to IDE adapter. They are WD400 caviars drives, not smart capable. So now that I have attempted to format them, I can no longer use the drives at all.... They were working fine before but were formatted in my old computer when installed as internal drives. I don't get it.