I had this problem years ago but have trouble remembering the solution. Maybe if you told us a little more information. If you don't mind?
Did this just happen?
Did you add anything to your computer lately?
Have you moved the computer?
Did you just build the computer?
Are you running PS/2 mouse and keyboard?
Do you smoke around your computer?
What is your blood type?
Sorry, the last is a joke
Now that I remember, I had the same problem with Win 95 while installing com ports for each device...IRQ's I think. You can't be having the same problem.
Please let us know the answers to the above questions and we will help. There's a lot of good and smart people here.
Your Hardware Guide.