Right click on your start menu

And select Windows Powershell (Admin)

Or Command Prompt (Admin)

Say yes when prompted

A blue or black window will pop up where you can type commands

In the Powershell or command window type the following commands

Chkdsk c: /f/r/x & press return

If you are running this command whilst windows is running you will see this message 

So click Y for Yes and then restart your PC

Windows will take  a little longer to start up whilst its running this command.

If it finishes without any errors then use your PC as normal and test to see if this has fixed the issue

If it reports any errors run the command again until there are no more errors reported. If it persists in reporting errors please let us know

If this completes without any errors but you are still having problems with your system move on to the next step

Type SFC /Scannow

This will attempt to repair any corrupt/damaged windows files

If it finishes without any errors or finds errors but fixes them move to next step

Type DISM /Online /Cleanup-Image /RestoreHealth

This will fix any corrupt files but also download any missing files it needs

Once complete run SFC /Scannow

Once completed with no errors your Windows installation should be repaired