New Windows 8.1 requirements strand some users on Windows 8
Source
A Guy
Windows 8.1 fixes many of Windows 8’s most glaring flaws, but not everyone is able to bask in the bountiful new features. Owners of some older PCs have found themselves stranded on Windows 8, trapped by a subtle tweak in Windows 8.1’s hardware requirements. And beyond the irritation factor, the issue could have troubling support implications for affected users, as Microsoft has told Windows 8 users they’ll need to upgrade to Windows 8.1 by 2015 to continue receiving critical system updates.
Source
A Guy