You may receive a Application not found message when you insert a DVD or USB or if you click on Hyperlinks in an email. If you do receive such an error, take a look at these suggestions and see which of these may apply in your situation.
Fix Application not found error in Windows
1] Edit the Registry
If you receive this Application not found message when you insert a DVD in your DVD Drive or connect a USB, you will have to edit the Registry.
So create a system restore point firsts and then Run regedit to open the Windows Registry. Now navigate to the following path:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer
In the right pane, you will see a MountPoint2 key. Delete it and restart your computer and see if the problem is solved.
2] Check USB Properties
If your Windows cannot access your external volume, DVD or USB, you may have to right-click on the Volume icon in the Computer folder and select Properties. Next, select the Hardware tab and click on the Properties button.
Now in the Volumes tab, click on the Populate button. If the operation runs successfully, you will see a This device is working properly message.
3] Run this fix
If you receive this message when you click on Hyperlinks in an email, you may need to set all the defaults for your default web browser. Do this and see if it helps.
If this does not help you, TechNet suggests the following:
Copy-paste the following in a Notepad and save it as Fix.reg file:
Windows Registry Editor Version 5.00 [HKEY_CLASSES_ROOT\exefile\shell\open\command] @="\"%1\" %*"
Then double-click on the .reg file and add its contents to your Registry. This will allow your Rundll32.exe file to function properly.
Let us know if you have any other suggestions.