The freeware known as Unlocker 1.85 adds itself to Windows Explorer for this purpose.
http://ccollomb.free.fr/unlocker/ Someone posted information on this in a response on another thread in the last day. When planning to clean a drive totall for a fresh install of XP or any other OS the best advice is to delete the existing partition or partitions on the drive and create the new primary for the clean install. The XP installer can be used for deleting the existing ones(MS Fat or NTFS) and creating new ones.