Solve "Access is Denied" error when opening .msc files

Today I got a very annoying error.


I tried to open services.msc and got the error:



The beauty of this error was the I was able to open the it through : My Computer :: Manage :: Services and Applications :: Services.

I googled through the error and found a lot of replies : Some of them suggesting some software restriction policy of the user not being Administrator and so on.
All did not apply to me as my computer is me personal home computer and not part of any domain and I was able to open it till a few days back (or the last time I openend it) and nothing changed in between.
So whats the issue. I am a Admin. I navigated to C:\Windows\System32 and checked the permissions for the services.msc file and as Admin I had Full Control over the file.

Then I found something special : I was able to execute "eventvwr" but not "eventvwr.msc" which gave the Access is Denied Error.

That was the Euraka moment. It had something to do the MS Management Control or "mmc.exe" which is used to open all these ".msc" files. I openend "mmc.exe" and loaded the snap-in "Services" and it loaded up fine.

Then the solution was simple :: The extension ".msc" has somehow lost the information that it needs to be "openend with" mmc.exe

So I did a right click on "services.msc" and selected "Open with". In the window I browsed to "C:\Windows\System32\mmc.exe" and phew it worked.
I checked "services.msc", "eventvwr.msc", "compmgmt.msc" and all worked fine.

Hope it works for you too :)