For those who used the registry fix to hack around the User Account Control restrictions, giving themselves full administrator rights will have to revert that last change. Although users can use the Windows 8 UAC user interface to seemingly give themselves full admin rights, they must go into the registry to make a final change.
However, that change means that Metro apps will no longer run. Unfortunately, when you click the Download button for Windows 8.1, you'll need to run ... a Metro app.
To change back, run regedit and set the key EbableLUA in HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\System (a DWORD) to 1.
There will be other hurdles, too, like extremely slow downloads as the Windows Store appears to be hammered, as well.
Windows 8.1 updates core apps such as Calendar and Mail, but there are also new apps, as well, like Health + Fitness. still, this isn't really a huge upgrade to the OS, but rather one that addresses criticisms about Windows 8.
For one, users will be able to boot directly to the desktop, bypassing the Windows Phone style Start screen. The Start button makes a return, too, but it doesn't behave as it did in Windows 7, when it would bring up the Start menu. Those wishing that sort of behavior should stick to apps providing those features in the Windows store -- those have been available since soon after Windows 8 launched.
Speaking of the Start screen, that gets a revamp as well, as it now provides more options for customization and layout. Windows 8.1 also -- and finally -- allows side-by-side multitasking of Windows 8 apps.
In terms of retail availability, rather than upgrades from Windows 8, Microsoft said that customers will be able to buy a boxed version of the software from tomorrow, Oct. 18, and that PCs sold from that day on would come with 8.1 pre-installed.