1. My computer is running slow
2. Can’t get onto the Internet.
3. Computer dials itself onto the Internet all by itself..
4. My  home page or default search engine has changed itself.
5. My computer locks up, freezes, or shows the Blue Screen of Death..
6. My computer keeps turning itself on all by itself.
7. My computer’s clock keeps losing time.
8. My My computer won’t boot.
9. computer spontaneously reboots itself..
10. My computer is making noises.

If you computer has any of these GBGeeks can help.