1. First unplug the power cord from the back of the scanner and plug it back in. The power cord is the larger of the two cords and is usually black.
2. Try scanning again. If it doesn't work move on to step 3 
3. Close everything you are working on.
4. Click the start button, then click log off
5. Unplug the power cord from the back of your computer. It is a large black cord
6. Wait 10 seconds
7. Plug the power cord back into your computer
8. Turn the computer or thin client back on 
9. Log back in as you normally would and you should be all set.