Lets start again ?

I clearly have a few deep problems with my pc and last time this happened a couple of years ago i just saved my files and made the computer clear itself and started all over again (i cant think of the exact phrase). Anyway i feel the time has come again due to things going real real slow and disconnecting dispite keeping my pc up to date with all the correct spyware protection etc etc.
Thing is i have forgotten how to do this thing to clear it and start all over again (i cant remember the right bloomin word and its annoying me
Can anyone help please? Or point me in the right direction to a tutorial. Thankyou.

 

I think you are referring to formatting (or reformatting) your computer. If you post what operating system you either have installed or would like to install, we can post some links to tutorials. It would, however, mean that all programs you have installed beyond Windows will need to be reinstalled.