.NET Framework corruption

After a system restore, the .NET Framework said that it needed to be repaired but it is never finished.
When I tried to install other version, it just caused a fatal error during installation.
I tried the repair tools, removal and even a repair install and all of them didn't work.
I just run sfc and no corrupted files are found.
I don't want to disable it and activate it again as a system restore needed to be done when I did that last time as I couldn't boot into Windows.

P.S. It is the version installed with Windows 7. Can't be removed accordingly.

The Microsoft .NET Framework Repair Tool detects and tries to fix some frequently occurring issues with the setup of Microsoft .NET Framework or with updates to the Microsoft .NET Framework.


If the repair tool won't resolve the issue lets uninstall and reinstall Microsoft NET Framework 3.5.1 let see if this will resolve the issue. Open Control Panel --> Programs and Features --> Turn Windows features on or off, clear the check mark for the Microsoft NET Framework 3.5.1 and click OK button. After uninstalling Microsoft NET Framework 3.5.1 restart your computer. After you login to Windows 7 open Turn Windows features on or off and place a check mark for Microsoft NET Framework 3.5.1 click OK button and restart your computer after Microsoft NET Framework 3.5.1 is reinstalled.

That's what I don't want to do.
Last time I did it, it just returned an error and I rebooted.
After rebooting, it just stuck with the booting GUI.
I went with system restore and a repair install and still have this problem.
I will try this again if I can't find any solution :)

First,open create a restore point. name it "repair" or something of your choice.

then, try @FreeBooter suggestion
or

open control Panel --> Programs and Features

scroll down list on right pane until find Microsoft .NET Framework (version) & select this with right-mouse click.

click on Uninstall/Change.

click the radio button next to Repair .NET Framework (version) to its original state. Then select Next.

Once completed reboot the computer

Or

If you encounter a problem, then Restore the computer back to the restore point you named "repair".

I will try this later
Thx for your help :)