safe mode boot up, configuration errors

I may have gotten a virus off the internet, I'm not sure, but my computer will not boot up in windows 98. It goes to a safe mode screen, then gives a c:/ prompt. I have no idea what to type in behind that. I tried typing in windows, but it gives back the answer as a bad command or file name. There is also a list of 3 configuration errors, which I assume is keeping me from booting up.

The 3 windows files that are corrupted are: himem.sys dblbuff.sys ifshlp.sys

What can I do to fix this?

Thanks, Don P.