If you use “corporate” Macs, you’ll often get frustrated with their “in-house builds” of OS X. The solution is to wipe the Mac, and install a clean OS.
But some have started to lock the HDs. So here are two ways to get around this.
Route one is to copy ZERO data blocks to the sectors of the Macs HD. You have to boot from Recover Disk/USB, and launch Terminal
dd if=/dev/null of=/dev/disks1 bs=512
Route two is a little different, but I’ve only tested Route 1. So if 1 doesn’t work, try 2.
sudo chflags 0 /Volumes/* sudo chmod a+rx /Volumes/*
After that, you’re free to format the drive and install a clean OS… Ahhh.. Clean OS.