Now use the Windows XP convert tool: Go to Start | All Programs | Accessories | Command Prompt (or, from a Run box, type CMD) and, assuming you intend to convert C:, give the command: VOL C: Note the name of the disk in the first line, and the Volume Serial Number (for example, 3F4E-2D1B) in the second. Then type: CONVERT C: /FS:NTFS It will ask for that name in confirmation. Then it will ask two further questions. Reply Y each time to set up conversion