I am having trouble Re-Installing OS X from either a backup or my orig. disks

I started having this problem when i found a wheel group hiding as my Guest User account. I have not been able to access root,su,sudo or anything. It's hides itself in the form of "Network". I have removed all my partitions, did a 7 times secure erase, no matter what i do it seems to find it's way into a new install.. Any ideas? or if someone could tell me how to boot from terminal using specific location please