computer hp desktop
how can i restore my hp desktop computer to factory?

i tried going to recovery manager, and it seems not to have one. i also tried shutting off and then turning on and hitting F11, it also did not work. what can i do? at this point to me anyway i tried everything and nothing. please find a way or if you have another way to go about it.i will appreciate if you do, and if you don’t thanks anyway.
system restore also did not work.it only takes you to an earlier date.

You need your original factory cd that came with the computer.
Or the OS disc.

Insert the disc and restart your computer.
When the computer starts it will run an install process. and wipe your drive and re-install your OS.
You will lose all files and information you have saved.