I spent a total of 5 hours installing Win 8 Pro using a Custom Install with format. I had to reinstall all my apps and update everything, including Office 2010 Pro with about 500Mb of updates. I also had to customize everything to my liking. I also created 3 Images using Acronis True Image 2013, 2 intermediate and a final when completed. All this was accomplished in approx. 5 hours.
I forgot to mention, this included the download of the ISO file and burn to DVD.
At some point you have to look at how many hours you are spending trying to chase ghosts around your PC and make a decision whether it would be more time effective to Custom install Win 8 Pro while saving nothing and starting over.
If you do decide to, make sure you back up all your data, or create a separate data partition and move all your data to the separate partition using the
approved method. In this way your data would not be affected at all by the reinstallation.
Once you have completed your reinstallation simply use the same method to change the pointers once again to the data partition. I have had a separate data partition for several years, and have restored the OS many times (I like to play with many different things and cause problems that an Image restore is quicker to solve) without affecting the data at all.
Once things are running properly (our 2 installations have been perfect from day one) start creating Images. I create a new Image of my OS once per month right after patch Tuesday so my Images are all fairly up to date.
I used this exact procedure on both our laptops and never looked back. In about 10 hours I had 2 pristine installations of Win 8 Pro including Media Center that have been perfect since the installation (over a month now). How many hours have you worked on trying to solve the problem?