Error: 0x80073712 when installing KB 2919355

"Do you think it's needed to use a generic key or can I use the legit key that came with the install media MS sent?"

EDIT: You may be able to use the activation key that came along with your install media, as I had forgotten you just received that from Microsoft a few days ago. Although, since you're not actually going to go through with the installation, it wouldn't matter which you use.

You'll have to use the generic... Windows 8 activation keys will not work to access Windows 8 installers once they're used to activate a copy of windows, nor will they ever work to allow access to the Windows 8.1 installer because Windows 8.1 is free, albeit for all intents and purposes it's a new and separate OS from Windows 8.  

"Also should I run WU up to the point where it's offering 2919355, then do this  procedure?"

If I understand you're question correctly, yes, install all updates available on Windows Update, except KB2919355.  Also, once you're down to only 2919355, please make sure to install the 5 individual updates that come as a part of the KB2919355 update package on Windows Update through their individual standalone installers.  Once you've installed the fifth one, restart, then follow the steps as listed.

Thanks again for your time and suggestions. Once I get a free chunk of time, I'll give it a shot.

Jim

"I have the ISO on my desktop. I'm not sure what steps to go through to perform the above step. Mount, Click and Run ??? Probably not that easy"

Yep, that's the correct thing to do =] once you enter the generic product key and click next, it should go to the "wait..." screen, give it about 5 minutes, then attempt the 2932046 update.  

I have no idea if this will work, as even though I installed all 5 standalones before 2919355, I wasn't made aware unless they are installed before 2919355, users will be unable to install them afterwards.  I added the EDIT within only a few hours of posting the tutorial, but I didn't catch it fast enough before users went through the tutorial.

"I have reset the windows update cache per your instructions with still no successful installation."

Worst case scenario, a system restore to before the 2919355 install should work, as windows always creates a restore point prior to installing any updates from windows update.  There may be other users that could give you in depth troubleshooting for this, and Ms. Bradley (moderator who posted above) may be able to provide in depth troubleshooting that I don't have knowledge of.  Although I know windows quite well, I'm a novice at best.  All of my advice thus far has come from my personal experience with the havoc caused by KB2919355.

In regards to the link, I didn't know that, I apologize.  It was a bookmark I had saved just for the instructions provided therein.  I would imagine there should be a way to get 2932046 installed without going through a system restore (although easy, is still a tad time consuming), but I don't have enough knowledge to know what could be done in lieu of a restore.

"However, there is now an ISO for Windows 8.1 Prowith Updateat the MSDN site, but none released to general public yet."

In regards to the MSDN editions, they only become available when someone on a software forum posts an iso they have from MSDN.  While moderators and microsoft frown upon users telling individuals to verify the MSDN hash, since it is a violation of forum policies and the terms and conditions of MSDN, something has to be done to allow users access to an 8.1 ISO, as it's literally the only way to fix the KB2919355 issue.