I fixed the issued by reinstalling Windows.
A fresh install was not needed.
But I had to use the "Keep personal files only" option.
The "Keep Windows settings, personal files, and apps" option did not help.
As a side note, I want clarify that VS12 does not have an Uninstall context menu item in the Control Panel\Programs. It only has "Change" which should normally bring up a menu listing "Repair, Modify, Uninstall".
So I installed Visual Studio 2012 on Windows 8 x64, but it is acting very weird when I try to uninstall it.
When I click on the only available option "Change", only a brief flash of the VS2012 logo flashes and then nothing.
I cannot install the Visual Studio 2012 Update 2 either. It does the same "flash" even with the "/layout" command from the command prompt.
I have spent over an hour trying to figure this out. I am at a loss here.
Edit: Cannot reinstall either. Even with the direct ISO from Microsoft, the same "flash" occurs and then nothing. Also I did a full Malewarebytes scan and nothing came up.
Edit 2: Safe Mode did not help at all. Doing a Maleware scan in safe mode, just for the heck of it. Nothing found.
Edit 3: I cannot install/uninstall/update anything related to Visual Studio 2012. Not the ISO, Web Download, or Web Install. Nor any version type or platform type. Not even Windows Update will work. Nada, zip, nothing. I was able to install Visual Studio 2010 again.