The Transformer book t100ta is brilliant on windows 10 pro x86 btw,
(The T100TA needs to be charged over 19 or 20% i think before you do this but definately charged above)
Before you follow this advice I recommend heading to the Asus website for the drivers and bios updates as there is a bios update to make it compatible with windows 10. To update the bios with the t100TA you have to use the tool built into the bios settings which you should be able to access either via installing windows 10 first as a workaround and holding shift down from the windows login page and use the power options on the bottom right to restart whilst holding shift down. or i forget which button to bash when you switch it on lol.
After the bios update re-do the windows install and wipe partitions etc.
After you install it let it run the updates and install the optional device drivers except the sound ones I had issue with the windows update version and had to uninstall them and use the asus site windows 8.1 version. You'll also notice that there will be a driver that can not be found which is the bluetooth driver but i'll attach the drivers i used which will cover everything missed or needed (all from the asus website by the way switching between the windows 10 pull down menu and 8.1).
As for activation am sure your resourcefull to figure it out (CMD activation) original windows downloaded iso.
after you have installed windows I recommend running ChrisTitusTech (youtube) windows debloat script from his github page along with the ultimate windows tools to really strip windows down to a minimum which helps with the 2gig ram and processor usage reduction a lot and remember to set the updates to security only so its not downloading all windows junk aswell.
The script i forget which one will uninstall winget for installing packages but re-starting one of them will reinstall it again also choose custom debloat and read through what you do not need like all the xbox stuff, etc just leave windows store unchecked and winget unchecked
so it keeps them.
(it will make sense more once you run the scripts and watched the tutorials on ChrisTitusTech page)
Also some personal preference settings I like is no sound on virual keyboard press, no backround processes runnung, dark mode all the time and start in tablet mode when not docked (if you leave this off you can easily switch using touch screen by clicking on the right notifications next to clock and expand the options at the bottom to select tablet mode plus all your bluetooth options are there aswell as others for hotspot etc (not checked the hotspot yet on mine but it appears to be working as it turns on etc)
And as the last resort if you haven't removed the recovery partition the original windows 8.1 files should be there but really recommend doing the above
Also this is the results in the screenshots below from my T100TA after doing the complete debloat tutorials. Boot up time is less than 10seconds, apps response on touchscreen and mouse usages is excellent, videos in brave browser all play at 1080 and some for some reason play well at 1440 lol
This reads like a lot of work to do but the reality is once you have prepared and learnt what to expect (i've covered the bumps i had so make life a bit smoother for you) the whole process from start to finish can be done in less than hour and you will be using the T100TA at its best by the end of it.
Hope you do this and not try to get it back on 8.1 its horrible lol and get back to me with the results or if you need other advice on the steps, would be good to see how the devices compare up against each other we might be able to improve the results better for both of us
good luck and have fun as i'm currently doing so typing this on mine lol.
As a last resort if you've not wiped your recovery partition you might be able to set the partition attributes to have a drive letter assigned using cmd command DISKPART and copy the wmi file from there to a usb and use the other machine to rufus create an install usb