Won't work when I try to Factory Restore

I am trying to restore my computer back to factory settings. I hit F8 and get to the proper screen but when I click Repair Your Computer it goes to basically the screen to login your user account asking for a different user account? Something like that, and when I type in my username and password it says it is not an account. I just want to restore it back to factory settings and it won't work. If anyone can help, thanks.

What is the model and manufacturer of your computer?