if this just started recently and it did work a few days ago please try a system restore to a time when it was still working. If that does not work or if it never worked please let me know and we can try some more advanced trouble shooting.
System restore instructions - windows 7 8 10
hold the windows logo key and hit R
in the box that appears type
select restore to an earlier date.
Under the "suggested restore" which is usually not old enough to help is a link for "OTHER RESTORE POINTS"
click that if the suggested ones are not BEFORE THE PROBLEM STARTED
choose a date from the calendar that is BEFORE you experienced the problem
hit ok / restore
the computer will start to shut down
a restoring settings box will appear with a status bar
when it finishes your computer will restart with the same settings it had on the date you restored to. your data will not be affected.
It is not perfect. But it fixes a lot of things.