I recently came across the nightmare that is hidden factory reset partitions on a shop bought PC myself when I tried to ressurect my sisters pc. Unfortunately the HD died before I was able to proper back it up, which in a nutshell is why the idea of hidden backup partitions is so stupid. Anyway, what I would do would be to forget about backing up the hidden partition, just do a factory reset and then backup the C drive as is with Ghost, call this your virgin backup. Then if you want install your drivers and stuff and ghost that partition to use as your main backup. Write these to a dvd and then get rid of the backup partition alotgether as to my mind it just takes up space and is no use as a safe backup anyway (see above)
In short get Ghost, you'll probably want to backup your c drive with it anyway before doing the factory reset.