I also experienced problems when I upgraded to Windows 8.1 from Windows 8 on my desktop but my laptop went flawlessly.

On my desktop, virtually none of my metro apps would work, I had to uninstall virtually all of them and re-install them. However, about five of them including Kindle and Crackle will just not work anymore. As well, a couple of apps I didn't previously have installed do not work on my desktop but work just fine on my laptop. I've tried almost every proposed solution I read so far on this site and updated my video card drivers to no avail.

If anyone else has any ideas please share.