SORRY ITS SO LONG AND KINDA RUN ON SENTENCES...
ok now as far as updating here is the best info I could find on how to update from the day you get your tablet. This is how I did it, and I only had 1 hiccup and Ill explain how to avoid that as well
HOW TO UPDATE YOUR ASUS VIVOTAB SMART ME400C and avoid major issues - it is best to start these steps from a brand new fresh tablet right out of the box, if you have tried and failed with asus live update and windows updates it might be best to use the restore point and or reinstall windows from the hidden recovery partition and start fresh again. You do not have to do this, but I highly suggest it. You might try it without the restore point/fresh install and maybe do it as a trial run and see how your tablet responds and maybe after you have done it once already save your files to microSD card and then do a fresh windows install/restore and try again to get no errors which like I said may result in a better tablet experience.
The most fool-proof way to upgrade it is by the following steps: READ ALL STEPS BEFORE ATTEMPTING so you can choose which option you want to try
(0) when you get it out of the box plug it in and make sure its charging and then power it on and on initial startup/setup, choose the option to "NOT" update windows.. This will prevent the 112 download updates. If you already past that point and have had your tablet a while with some failure and some success your best option maybe to go back using the restore point feature or reinstall from the recovery partition and start fresh again (YMMV and look below for the info on where the recover partition can be found)
(0.1) click the desktop tile and it should prompt you to Run vivotab live update and only update the bios and it will need to restart/reboot. This did give me an error and I had to use restore point to start over and so I found the asus live update Version V188.8.131.52 off a forum, but didnt save the link so you can search it out yourself or I found it here ASUS V184.108.40.206 Drivers LiveUpdate21313.zip - ASUS Downloads - DriversGuru I used the 2nd download now link which is 7.4MB version bc thats what I remember the file size being from my successful attempt - you can also try to get it off the asus website but I wasnt having any luck finding it before posting this step by step
(3) if you were successful with the bios update or did the uninstall live update restart and then install from the zip file you just downloaded then click desktop tile again, asus live update and do the bios for the 1st time or the remaining updates and restart. ( basically uninstall live update, reinstall from the zip, do the bios update, restart, do the remaining update and restart.) if all that goes well go to step 4!!!
(4) just do a google/bing search for KB2871389 - download it from the microsoft download center and then search for KB2917499 and download it from the microsoft download center - make sure to choose the x86 versions bc the VivoTab Smart is a 32bit version of windows 8 - install them in that order.. cant remember if it asks you to restart after each, but do it if it asks of course.
This will allow you to get 8.1 update from store.
(4) Go to the tile interface and click on the store tile and select the 8.1 update to install, its something like 2.7 GB and will take a while to download and install, restart and then you get to set your preferences - I suggest doing customize when it asks so you can have more privacy etc, but to each their own.
That's it... 8.1 loaded. WHEW what a crazy way to just update to 8.1, not too happy with ASUS at this point, it should be seamless but alas nothing ever is, right?
I hope that all made sense and was detailed enough to help the many people who may be searching for how to fix the errors they are getting and make it simple and easy!
edit - impt info
I also forgot to mention above that after you do install windows 8.1 you should have a windows.old or whatever its called folder on your hard drive (c drive most likely as I dont remember exactly where windows leaves it) that will have your old stuff from windows 8 that you should probably move any files you had on the asus before updating to windows 8.1 and then delete the unnecessary stuff that is left and get some storage space back.
THEN after you get your tablet up to snuff with windows 8.1 updates (and if you want your programs and such) then DO A FULL IMAGE BACKUP so if all else fails you can always try to revert to that complete image backup you made and not have to do the nightmare of all the steps above. There are free image backup programs, I believe windows 8.1 has its own way of doing this etc then there are paid programs so you should do your research and find what option is best for you and compatible with windows 8.1!