The Windows app store is by far the easiest thing to break in Windows. You can tell they rushed it out the door.
As an example, when I was looking for a way to do repairs for the App store MS doesn't list a single page on info the app store needs. And if a folder is missing the store needs it will simply fail instead of creating the folder it needs.
Also I had to disable my Reset reg permissions repairs because there is some keys, I haven't found them yet, that if the permissions are touched in any way will cause the app store to fail. And it isnt a permissions issue, it is a "Hey this isnt what I wanted" problem. Most likely some sort of DRM on their part.
SO if even 1 folder or file is missing or any permissions are touched the app store breaks, that easy.
I would love to make a repair for it but Microsoft wont list anything about it. The only answer they give is to do the Windows 8 Refresh. Which so far is the only way to get the app store working again.
I have ran all my repairs on a fresh install of Windows 8 and only the reg permissions was the one to cause any problem. All others worked fine.
I am hoping as time goes on and 8 is out more I can finally start finding what files, folders and regkeys the store needs, then I can make a proper repair for it
Shane