Wanting to clean hard drive but keep operating system

I want to whip my hp pavilion dv2700 clean but keep operating systems. Any idea's on what i may can do i no longer have disk to back up. When i go to system restor for hp and click on it it does nothing.

 

If you do a factory reset after backing up your data. You said you did a system restore. This is not the same thing as a factory reset where everything is reset to factory state. You can do it inside of windows or by pressing F11 at boot.

http://h10025.www1.hp.com/ewfrf/wc/...seCategory&cc=us&dlc=en&lc=en&product=3559543

 

I gave the hp to my dad who has royally messed things up. I was trying to write two different thing. When i go into windows and do it through there it does not do anything. I will try the f11 and see how that does thanks.