Windows 8.1 is Released but be warned!!!!! It will NOT operate on all machines. From the FAQ:
Windows 8.1 Preview works great on the same hardware that powers Windows 8:
Processor: 1 gigahertz (GHz) or faster
RAM: 1 gigabyte (GB) (32-bit) or 2 GB (64-bit)
Free hard disk space: 16 GB (32-bit) or 20 GB (64-bit)
Graphics card: MicrosoftDirectX 9 graphics device with WDDM driver
Windows RT 8.1 Preview requires that you have a PC already running Windows RT with 10 GB of free storage space.
Warning:
In order to use Windows 8.1 Preview you must sign in to your PC with a Microsoft account. The option to create a local account will be made available at the final release of Windows 8.1.
Additional requirements to use certain features:
For 64-bit installations of Windows 8.1 Preview, your CPU must also support CMPXCHG16b, PrefetchW and LAHF/SAHF.
To use touch, you need a tablet or a monitor that supports multitouch.
To access the Windows Store and to download and run apps, you need an active Internet connection, a screen resolution of at least 1024 x 768, and a Microsoft account.
Internet access (ISP fees might apply).
Windows will check your system's eligibility before you update to make sure your system can support Windows 8.1 Preview.
The reason I state this, Windows 8.1 says my PC is incompatible. Now this could be due to many factors. Such as a 3rd party AV. It could be due to some of the programs I have installed are not compatible with the update. It could be due to the fact I have modified the Registry cause of my SSD installed. But for whatever reason, I cant just manually upgrade to 8.1 thru the Store. I have to download the ISO and install it fresh.