Windows 98SE will not start

Hi,
Now I am not able to start my Windows 98SE. I suspect it reports wrong size of free space. First a scandisk showed a problem with boot-sector, and repaired it. Before this, free space seemed to dissappeaer just like that, and it went from 800Mbto 95Mb in no time. McAfee does not find any virus. Scandisk and defrak did not help. Now I can only start in safe mode.
Grateful for any advice!
Ove