Microsoft Emphasize Signature Edition Tablets
Microsoft started emphasizing Signature Edition tablets, 2-in-1 tablets, and other computers that run Windows today in their own Microsoft Store.
A Signature Edition Windows computer is a clean install of Windows without additional trial software that expires after 30 days or so, or other trialware and often annoying software that you may never use, and that clogs up the computer by using much of the capacity of your processor and RAM, even if you're not using the software itself.
So, Signature Editions deliberately rejects software that isn't Microsoft's own, but not Microsoft software like Office which is still included with most Windows tablets today.
See which Windows 8.1 tablets that are affected so far here:
http://www.microsoftstore.com/store/msusa/en_US/list/Tablets

– Tom Bowen

Jim's passion for Apple products ignited in 2007 when Steve Jobs introduced the first iPhone. This was a canon event in his life. Noticing a lack of iPad-focused content that is easy to understand even for “tech-noob”, he decided to create Tabletmonkeys in 2011.
Jim continues to share his expertise and passion for tablets, helping his audience as much as he can with his motto “One Swipe at a Time!”