Open Start, type: CMD
Right click CMD
Click Run as administrator
At the command prompt, type:
net stop vss
Hit Enter then type:
net start vss
Exit the command prompt then restart the computer, try backing up again.
If the problem persist, try the following:
Open Start, type: CMD
Right click CMD
Click Run as administrator
Type in at the prompt OR Copy and Paste these one at a time : (Hit enter after each)
Dism /Online /Cleanup-Image /CheckHealth
Dism /Online /Cleanup-Image /ScanHealth
Dism /Online /Cleanup-Image /RestoreHealth
Also run the System File Checker utility:
Open Start, type: CMD
Right click CMD
Click Run as administrator
At the Command Prompt, type: sfc/scannow
This will check for any integrity violations
Restart your system