Run .NET Repair:
Microsoft .NET Framework Repair Tool
If You still have issues:
Please run the System File Checker (sfc) with these steps:
- Click the Start orb and then type cmd in the Search programs and files field.
- In the results area, right-click cmd.exe, and then click Run as administrator. You will be prompted to type the password for an administrator account. Click Continue if you are the administrator or type the administrator password. Then, click Continue.
- At the command prompt, type "sfc /verifyonly", and then press ENTER. This will just scan the system. If it finds issues and you need to repair, run "sfc /scannow".
The scan may take some time, so be patient. Windows will repair any corrupted or missing files that it finds
ONLY FOR NovaBACKUP PC (formerly 'Professional').
If that does not help, try this utility:
Tweaking.com - Windows Repair
It is a free Utility that can repair Windows
Tweaking.com - Windows Repair is a tool designed help fix a vast majority of known Windows problems including; registry errors, file permissions, issues with Internet Explorer, Windows Updates, Windows Firewall and more. Malware and poorly installed programs can modify your default settings resulting in your machine working poorly - or worse. With Tweaking.com Windows
Repair you can restore Windows original settings fixing many of these problems outright.
Video on how to use utility,courtesy of MajorGeeks: