You don't have to disconnect the battery cable.

You can just pull both fuses for the radio, and it will force the software reload as well. That way you keep all other information the car has learned.

I used a BenQ drive I got from CompUSA, but it is a desktop drive

I could not get my Samsung or Sony drive to work, but the sony drive was a first generation DL drive I got when the first came out (Cost me like $600 at the time, but the BenQ was less than $50.)