There may be a program running in the background causing this issue to occur. Rebooting your computer without your normal startup applications running may resolve this issue. To do this, please follow these steps:
1. Put the cursor over the Windows Start button and press the right mouse button and click on Control Panel with the left mouse button.
2. In Control Panel, click on System and Security.
3. Click on Administrative Tools.
4. Click on System Configuration.
5. If you are prompted for an administrator password or confirmation, please type the password or provide confirmation.
6. Click on the General tab.
7. Click Selective startup and then uncheck the Load startup items check box.
8. Click Apply and then OK and then click Restart.
9. Open the MF Toolbox at this point and attempt a scan.
To return your computer to normal startup mode, follow steps 1-5 above, put a check in the box next to Load Startup Items, and then choose Normal Startup (if it was set this way initially) and click Apply. Click on the Services tab and click on the Enable All button. Click Apply, then OK and restart your computer.
If you continue to have difficulties, please contact our support group using the following link:
http://Canon.us/ContactLI