I have a small 20gb hard drive with about 10gb free space. If I use the single pass Drive Wiper everything finishes perfectly. However, if I select the three or seven pass wipe, everything goes OK up to about 50 per cent done, but then CCleaner suddenly stops as though it has finished, even though there is still about fifty per cent or about ten minutes to go. This has happened on at least six occasions. I have uninstalled and re-installed CCleaner. I use WindowsXP with SP3. I also use MilShield, shareware, which runs perfectly for one, three or seven passes. Why do I wipe the free space so frequently? I don't get out much.