Help - Windows 98 - can't boot up

[ErinMC]

I am running Windows 98 on an old Compaq Presario. Prior to this problem, I'd had a few virus problems and very slow system, but I *thought* that was all cleared up. Apparently not.

I am unable to boot up to the desktop. The Windows 98 start-up screen churns through, but it brings me to my wallpaper and freezes. No icons, no start menu, nada.

ScanDisk found no problems. I have plenty of hard drive space. I have tried starting in safe mode and get the same problem. I CAN work from the command prompt and see all of my files, so I know they're still there. I have also run the step-by-step confirmation and all goes through correctly, it still freezes on the desktop load.

Any ideas of what to do? I just tried to go back to a previous version, but the restore failed. Someone suggested it may be a problem with the explorer. exe file - how do I fix that?

TIA!

ETA: I tried getting into the bios to run a boot disk but am unable to get in - I keep hitting F1 but nothing happens. When I stop hitting F1, windows continues loading.