First, try a System Restore...don't worry, it won't touch your personal files..just the system settings.
Go to Start, Control Panel.
Type System Restore into the search box and chose the second option under System.
It should be:
Restore System Files and Settings from a Restore Point.
Choose it and then pick a restore from before the problem started. If that doesn't work...like if a message comes up saying System Restore didn't complete properly, you need to try it again with a different approach.
You may want to write these instructions down:
1. Restart your computer.
2. When it starts up again press F8 repeatedly before it hits the loading screen.
3. Select the first option.
4. Log in as your usual user (I am unsure what the Admin pass is)
5. Select System Restore and select a date before the problem started.
~If you cannot see the system restore, move the main box out of the way.~
6. Let is restore and hopefully the problem should be fixed.