Microsoft released Windows 8.1 Update on April 8. The Update is free through Windows Update.
See http://windows.microsoft.com/en-us/windows-8/install-latest-update-windows-8-1 for installation instructions.
Vanderbilt departments can order Windows 8.1 Update through the Software Store by placing an order under the Departments tab.
Note that Windows 8.1 users must install the Update version by August 12 in order to continue to receive security patches, product fixes and updates.