lets try this as a first attempt at repairing the issue.
1) Launch Control Panel
2) Under "System and Security" click "Review your computer's status"
3) At the bottom of the following window click "Troubleshooting"
4) On th next window click "Run programs made for previous versions of Windows" under the "Programs" header. This will launch the "Program Compatibility" app.
5) Click "Next" and select the program "Canon IJ Network Scan Utility"
6) Click "Next" and then click "Troubleshoot program"
7) Check the box next to "This program worked in earlier versions of Windows but won't install or run now"
8) Click "Next" and select "Windows XP (Service Pack 2)"
9) Click "Next" and click the "Start the program" (windows will ask you if you want to allow changes, hit yes.
10) On the following screen "Troubleshooting has completed. Is the problem fixed?" click "Yes, save the settings for this program"
11) Click close on the next window.
Now repeat the same steps for the program "MP Navigator EX 3.1".
Let me know if you get stuck, or run into any issues.
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