Disable Pointer Trails.
I had the same problem and couldn't figure it out for the life of me. Here might be your fix.
1. Go to your Windows Control Panel and click on your Mouse Icon to bring up your "Mouse Properties" window.
2. When your "Mouse Properties" window comes up, go to the "Pointer Options" tab.
3. Go down to the "Visibility" section at the bottom of the window and you'll see the first option in that section that says "Display Pointer Trails".
4. Uncheck the "Display Pointer Trails" option and save your changes by clicking Apply or OK.
5. Try your Full Screen App or Game. Your mouse should work properly now.
If this doesn't fix your problem, try running your app in "Windowed Full Screen". This will work for sure. Your mouse is most likely still working, but you just cannot see the cursor. So, you may have to fumble around, while in full screen mode, to get to the application options, so you can make the change to Windowed Full Screen mode. Also, you can try using your esc key to bring the app out of full screen mode. Sometimes this works.
I hope this helps. If not, good luck. I hope you get it figured out.
Sincerely, Rich Williams
DomainMasters.NET Web Hosting