Give credit to Microsoft for a quick turnaround -- after pulling its glitchy Windows RT 8.1 upgrade this weekend, the company has re-released the software in the Windows Store. The new version should eliminate the (as yet unconfirmed) boot configuration flaw that forced some users to restore their PCs. If you're eager to finally update that Surface RT, you just need to check for the update on your device to start downloading.
Microsoft Windows RT
Microsoft Windows 8.1