Scandisk in safe mode

I have WIN98SE, PIII/550mhz/128MB,when I perform thorough scandisk in safe mode after disabling screensaver & Norton Antivirus 2002, scandisk stops midway and informs that it cannot proceed as some programs are still running even though none of the programs are running when I check by CTRL-ALT-DEL method. Please advise what could be the problem be. Thanks – K F Dholoo