That partition was likely put there by the manufacturer to help you restore the PC to factory specs if you ever needed to do that.
If you in fact deleted the partition and do not have "recovery disks", you will have problems restoring to factory specs.
Do you have any install discs at all? What happens if your hard drive fails in 30 minutes?
System protection is not the same as "system restore", which you may be thinking of. System restore returns the operating system to the way it was on the date the restore point was made---typically somewhere in the last couple of weeks-----not to factory specs. System restore points are stored on your C drive along with Windows.
Can you post a screen shot of Disk Management?