According to a post on Microsoft forums (via Softpedia), updating your PC and Windows RT devices to Windows RT 8.1 Preview will require a PC already running Windows RT with 10 GB of free storage space.
Microsoft has already received complains for limited free hard disk space in their Windows Tablet PCs in the past.
Here’s how much hard disk space you have available out of the box:
It appears that another explanation will be required. Softpedia pointed out that, “a 32 GB version of the Surface RT has approximately 15 GB free hard disk space, which means that your installed apps, settings, and files should eat up a maximum of 5 GB on your disk in order to install the 8.1 Preview.”
Check out this Pocket lint report on what to expect from the new system.
According to the report:
The Windows 8.1 preview release date has been confirmed by Microsoft as 26 June, following the Build developer conference in San Francisco.
The preview will be available for Windows 8 and Windows RT. As you would expect Windows 7 users will have to upgrade to Windows 8 before then trying out the Windows 8.1 update.
The final update is likely to be available later this year with the smart money being on around the first anniversary of Windows 8, or in other words Christmas 2013.