Qarl’s texture pack III problem

I am have a problem trying to get the “Qarl’s texture pack III” to work, and it is driving me CRAZY. In the past, I have managed to make this pack to work flawlessly, but after a catastrophic failure with a mod and spending hours trying to figure out how to fix it, I had to uninstall everything. I downloaded the “Full Pack” that only used 1 OMOD file (compared to the 11 parts from the NEXUS). After waiting 3 hours for the 1.7Gb file to finish downloading, I ran OBMM and selected the OMOD file. After that I ran Archive Invalidation (with BSA Alteration and all of the necessary boxes checked as written in the README.txt file) and closed out. When I started up Oblivion, there was no noticeable change in the way things looked. What happened and how do I fix this?