Is it possible to restore aspire one zg5 to default settings without losing any files?
No. You’ll need to backup all of your files to a CD, DVD, Flash Drive, or external HDD before you restore the unit back to factory settings. It’s a shame it didn’t come with Vista or 7, you could do what they call an “In-Place Upgrade” it would reinstall Windows, top to bottom, and save all of your files and settings. XP does not have that capability. So you’ll have to back up all of your files before you can do the restore, or you’ll lose them in the process.