I've tried running: uninst.exe /S (using "capital" S) - appears like it's doing something, but then I look in add remove programs and it's still there. No errors are displayed, just drops back to the command prompt DOS windows. I have version 5.04 installed (I've tried it on 64bit and 32bit.) same lack of result. Any ideas why that command line switch doesn't work and if so, how to do it from command line (so user doesn't see Ccleaner uninstall)? Thanks!