"Even though it might not come in handy for some beginners, there's already a workaround that requires users to follow some steps to correctly install the firmware update.
First of all, you need to open a Command Prompt window by right-clicking on the Start button and then type NET STOP WUAUSERV.
Secondly, go over to C: > Windows > SoftwareDistribution > DataStore and delete the datastore.edb file.
Next, go over to the Start screen, type “disk cleanup” and launch the built-in utility to clean up system files and Windows software updates. The process should take only a few seconds, depending on your hardware configuration and the number of items to be removed.
Next, reboot your Surface Pro 2 tablet and then launch Windows Update once again."
The main question at this point: has anything changed in the way your SP2 is running? As we know after the Dec 10 firmware installation failed, it caused SP2's to behave erratically sleep, battery drain, etc.
Not really sure what your next step should be. Other than trying MS technical support. I expect some others here will have more specific advice.
Hi, my sp2 failed to install 10/12/2013 firmware update and has been working OK up until today when it failed to install 18/01/2014 firmware update. After that it was showing plugged in not charging 0%. I followed vol+ and power button press for 15s, as on: How to Fix Surface Pro 2 ?Plugged In, Not Charging? Error but no joy. Then I did it again after removing type cover and bingo, restarts with battery apparently all OK. The firmware update 18/01/2014 then succeeded and all seems good again (fingers crossed).
I had a failed firmware installation but it succeeded on the subsequent attempt.
For me, though, this is consistent behavior with other Windows updates: Sometimes I'll see several failure attempts but eventually it will be successful. Who knows what it was that caused them to fail but, eventually, my system was in the right state at one point when a subsequent attempt was made and the updates were successful.