With Windows 8.1 generally available, those with Windows 8 Enterprise have noticed that they cannot upgrade their OS to the new version using the normal Windows Store-based installer. Here's what you need to know to get upgraded to Windows 8.1 Enterprise.
First, and most generally, Windows 8 Enterprise is "blocked" from using the Store updater for good reason: Enterprise is rolled out to users in controlled corporate environments only, and the admins and IT pros in those environments will determine when—if—that upgrade occurs. There's no "switch" or whatever that I'm aware of that will overcome this limitation.
You can read Windows 8.1 Upgrade Guide: Electronic Upgrade Options and Windows 8.1 Upgrade: Step-By-Step for more information about using the Store-based installer.
But what you're concerned with, as a Windows 8 Enterprise user, of course, is how you can get the upgrade.
According to Microsoft, those with Windows 8 Enterprise can download Windows 8.1 Enterprise media from the Volume Licensing Service Center (VLSC). This media, which is delivered in the form of an ISO file, can be used to perform an in-place update from an existing Windows 8 Enterprise installation: Just burn it a DVD or copy to a USB key for installation.
(Note: If you acquired Windows 8 Enterprise from TechNet and MSDN, you can of course use your subscription to grab Windows 8.1 Enterprise now and perform the upgrade in a similar fashion.)
From an admin and IT pro perspective, corporate environments can use this ISO to deploy the upgrade to users via the Microsoft Deployment Toolkit (MDT) 2013 or System Center 2012 R2 Configuration Manager. These environments will also need to update their existing Key Management Service (KMS) server and get new KMS keys from the Volume Licensing Service Center (VLSC) to activate Windows 8.1.
For those interesting in checking out Windows 8.1 Enterprise, Microsoft is offering a 90-day Evaluation version. And for more information about this product version, be sure to visit the Windows 8.1 Enterprise Evaluation Resources site.