Error 0x800705AA when you try to upgrade a Windows 8-based virtual machine to Windows 8.1


You can’t upgrade a Windows 8-based virtual machine that is running in a Virtual Desktop Infrastructure (VDI) environment to Windows 8.1. Additionally, you receive the following error message when the virtual machine restarts during the upgrade:

Couldn’t update to Windows 8.1

Sorry we couldn’t complete the update to Windows 8.1 We’ve restored your previous version of Windows to this pc.

0x800705AA – 0x2000C


Certain phases of the upgrade require more memory than the default startup RAM (512 megabytes [MB]). This issue occurs because dynamic memory isn’t enabled during those phases of the upgrade.


To work around the issue, increase the startup RAM for the VM to 2 gigabytes (GB) in the Hyper-V manager before you upgrade. You can set the startup RAM back to the default after the upgrade is complete. 

More Information

For more information about dynamic memory, see Hyper-V Dynamic Memory Overview.

Article ID: 2878739 - Last Review: Jul 29, 2015 - Revision: 1

Windows 8.1, Windows 8.1 Enterprise, Windows 8.1 Pro