Try to download and run Microsoft's .NET Framework Repair Tool.
After that perform the following:
Click on Start menu
Type command to start searching
Right click on command prompt in list and select Run Administrator
Copy and Paste each the commands below into the command prompt
sfc /scannow (best to run 2-3 times, rebooting after each time)
(Windows 8 or higher)
dism /online /cleanup-image /restorehealth
When these have completed.
Right click on the top bar command window
Left click on Edit then Select All
Right click on the top bar again
Left click on edit then copy
paste into your reply
If any Errors are found with sfc /scannow then:
Type the following command, and then press ENTER:
findstr /c:"[SR]" %windir%\Logs\CBS\CBS.log >"%userprofile%\Desktop\sfcdetails.txt"
Upload sfcdetails.txt from your desktop