Hello friend how are you? Actually I've faced this problem. The only way to get rid of this, is to install windows 98 again. Remember, do not use the same CD or Setup(saved on you hard disk) from which you install this time. Do install from different CD. Try to get latest windows 98 CD from the market.
Be sure to save your data and format the drive where you want to install the windows before insalling new copy of windows.
Hope this will solve your problem.
Take care of you and others and be happpy.
Bye...
Dur-E-Wahab