I would like to perform a factory reset on my Gio @5.
If your Gio @5 is running Windows 7, you will need to request an Eos Family Re-Image kit from ETC Technical Services.
If your Gio @5 is running Windows 10, it has a built-in recovery process that can restore the hard drive to the version of Eos that was current when your console shipped. Instructions for this process can be found here: Gio @5 Windows 10 Factory Restore.
Following the steps in the Factory Restore instructions will completely erase your console's hard drive before restoring the base operating system and software. Be sure to back up your data if possible before proceeding.