Restoreing to factory settings

Try this: Immediately after turning the computer on, press F11 continuously until a "PC Recovery" console begins, then choose the options for "destructive recovery", this will reformat the hard drive and restore the operating system to factory settings.
On some computers, it is the F10 key. This has to be pressed right after you hit the power button.
Also, remember to back up anything and everything you may want to keep, because this will erase ALL data on the machine.

You will need to reinstall the OS (operating system) by using the disk that came with your system, it may be called a restore disk or operating system, and their may be more than one disk!