1. Check drivers
2. Check Hardware Connection
3. If you have Windows XP and can restore back to a date where you remember it working do that. Oddly enough this does work once in a while.
3a. If you have Windows 98 or Win Me do a dirty re-install by going into C:\WINDOWS\OPTION\CABS\setup.exe
**You need to have your Windows Product Key. You can get this by going to run, type in "regedit" search the registry for "productkey" once you find this write it down, it will be something like
"A92S1-A4F68-GDF45-AD6AS" it should be in the "LOCALMACHINE\SOFTWARE\MICROSOFT\WINDOWS\CURRENT_V ERSION\"
part of the registry.
4. If you think it is virus related download AVG free edition from
www.grisoft.com and run it. Works great and doesn't cost anything.
5. If your browser is highjacked download CWShredder.exe, highjackthis.exe and run them.
6. AdAware 6.0 is a great tool for removing spyware.