|Make and model would be useful info to post as well…|
And if heeding phil22's warning about losing all data when you do a factory reset… If you haven't copied all those important (I don't want to lose them files) before the problem started… you can probably still get to them and copy them off to external media (typically DVD).
Boot up with a Ubuntu (or similar Linux DVD) and copy the files to DVD. Linux loads itself into RAM only and the hard drive is accessible as resource to Linux OS.
Then go about reseting back to factory state - if needs-be.