Sometimes this will happen if you have a boot sector problem.
If you have a windows 98 boot disk, boot to the boot disk
then sys the c drive before installing 98.
Boot to A: then type SYS C: If it works it should say System transferred.
If it does then take the diskette out of the drive and let
the computer boot. It should come to a C: If it doesn't then
you have a problem with boot sector. If it does then try to
reinstall you windows 98.
You might check for a virus or fdisk and format your drive.