Restart the computer in SAFE Mode.
1. Start Command prompt from Start - All Programs - Accessories.
2. Type the following commands:
cd\windows (then press enter)
copy regedit.exe regedit.com (then press enter)(note space after copy and after exe )
start regedit.com (then press enter)(note space after start)
3. Now, navigate to and select the following key:
HKEY_CLASSES_ROOT\exefile\shell\open\command
4. Double-click the (Default) value in the right pane.
5. Delete current value data, and then type: "%1" %*
6. ok
If all went well you should then be able to run the .exe files.