I reckon if you go back to Factory settings your hard drive will over write the C drive completely.
You will need an external drive to do any back up.
Have a look in programs under the computers name mine been a Samsung has its own tools. Basic Restore, or compete Restore, and Data restore.
Before loading any programs reload the drivers that should be on one of the disks.
The XP disk should do it all for you though including drivers.