Removing HPA

I've been investigating various methods of removing the Host Protected Area (HPA) from my laptop. The two sites I've come across involve one of the following methods:

* Zero'ing the hard drive with

Code:

dd if=/dev/zero of=/dev/sda

* Run Hitachi Feature Tool boot disk after your restart, using the change capacity feature, set it to Max; then zero your hard drive
* Use HDAT2

I obviously can't test any of these until I've set up my backup properly, but I was wondering about the first method: isn't HPA a ATA-level feature, i.e. zero'ing the hard drive will delete the partition, but won't it still lie about theoretical and max sizes?

A little context: cat got on my computer and pressed the Dell MediaDirect button, which hosed my BIOS, probably because of my Ubuntu dual-boot. Now hibernate is funky (the magic combo is boot up with home, then use the power button) and my partition table is fscked up and etc etc etc. So I'm going to do a full reinstall, get the partitions right, and get rid of HPA.