Can’t Open Regedit.exe?
If you cannot open the registry editor (regedit.exe), your computer may be infected by a virus or malware.
Some viruses and malware block access to the registry and to Task Manager to stop the average to moderate user from stopping or removing the infection.
If your antivirus did not prevent the infection or you do not have antivirus protection installed, you will need to fix the problem manually.
The following are methods of fixing the registry so the registry editor and/or executable files (.exe) can be opened:
Rename the file
Renaming the file extension of regedit.exe to regedit.com can enable you to open the registry editor so you can remove the bogus entries that are causing the registry editor and/or executable files from opening.
Removing the bogus entry in the Registry
Open the registry editor and find the following entry:
Find the “.exe” entry and right-click it and click delete. You should now be able to open executable files (.exe) with no issues.