fix computer errors

It depends on what option you choose. In the Windows XP setup disk it will ask you if you want to repair or load it to a new installation (deleting your existing data).
If you see something else when you put your recovery disk in, such as a manufacturer logo, then you are probably in their recovery mode and most of them will completely restore the hard drive to the factory settings.
I would contact the manufacturer of your computer by going on the website and search for “reinstall windows” or “reinstall operating system” to read about the specific options that are available to your computer as most of the manufacturers do it differently. Good luck and be careful – read all of the information on the screens carefully so you know what is going to happen!