|Are you also aware that the factory restore/reset routine will erase "all" your personal files in the process?|
So if there's anything on the drive you'd like to preserve/save... then first copy it to external storage . typically to DVD but an external hard drive too is nice(r).
Verify the copies are accessible on at least one other working system (if possible). Then you can set about the factory restore/reset knowing "your" personal files are safe elsewhere. Those files can be copied back later the the hard drive.
And develop the habit of "regularly" copying personal files to external storage; just incase something goes amiss/wrong with the system at any time... and you're unable to access/save those files... Regularly check the copies are OK; updating as necessary.