[Windows 8 General] Braccoz:
hi guys, i finally received the tablet (FB4M version) and am currently working on it to get the setup i want (dual boot, english win8.1 with oem key). im gonna keep this post updated as i progress, to make it sort-of a guide for other people.

First step: backup everything

i created a USB flash drive with REFind (http://www.rodsbooks.com/refind/) by downloading the image and writing to a usb drive (that will get deleted) with usb image tool

then, i used a usb hub on the otg port of the tablet to connect mouse, keyboard, that usb stick and an external hdd that i had preloaded with a custom WIN8PE build of mine that contains disk imaging softwares. (note that the 8pe is 32 bit and the bcd files are correctly set up to allow uefi and mbr booting)

after powering up the tablet, i connected the hub with my stuff and went into charmsbar -> change pc settings -> update and restore -> restore -> reboot. then "use another device" and then i selected my usb stick with REFind on it, then from REFind i chose to boot my Win8PE disk (note: the win8pe disk should have been able to boot directly but apparently can't for some reason)

after i got into in win8pe i used a disk imaging tool to make a full image of the stock Win8.1 with Bing, just in case. full image compressed is ~5GB

rebooted into stock 8.1, installed the taipower tool to make a backup of my windows key in the bios. the software is in chinese but apparently the first option is to save the key and the second one is to restore it.

the saved key is a short bin file that contains few blank characters and the actual key which is surprisingly in plain ascii, and is exactly in the format you see on stickers (XXXXX-XXXXX-XXXXX-XXXXX-XXXXX) note that the key is the same that you see with some windows tools that can get it from the running system (i used jbkeyfinder)

i then proceeded to do a backup of the whole firmware by using the fptw.exe provided with the FB5M bios (fptw.exe -D filename.bin)

at this point i got everything backupped so i should be able to restore the tablet to full stock condition in case anything goes wrong.

Second Step: upgrading the BIOS

this one is really simple, i just ran the flash.bat file (as administrator) found in the BIOS update package.

rebooted (manually, the tool doesn't ask for reboots or anything)

bios is now dual boot, but alas lacks a lot of options (my guess is that they have just hidden the menus. there should be a way to unhide them, either with some key combination or by using the AMI bios editing tool and re-flashing... will get to that later)

Third Step: Restoring the key

after the bios update and reboot, i opened the taipower bios key tool and selected the 2nd option, chose my key file i previously saved, ignored a checkbox under the file selection (left it blank) and finished the procedure that restored my key. to verify that it indeed restored the key in the bios i did the dump procedure again and compared the file with the one i extracted before the bios upgrade: they are identical, so it's a success

Fourth Step: Installing Android

for this one, i just followed the guide posted by Jazk which i'm more or less shamelessy quoting there:

IMPORTANT

i STRONGLY advice you to install any OTA update right before rooting (point 13) and absolutely BEFORE installing Windows. doing the OTA update not only removed root but screwed up my Windows installation too so be careful

a couple notes about this, however.

if the VID/PID image is too blurry to read, the values are: 8087 and 0A65 first row and 8087 and 09EF second row

i chose the 6gb partition file just to find out later that 6gb refers to the data partition only, which makes it a total of 9+ GB for the whole android system. so keep that in mind, whichever partition size you choose, it will take ~3GB more.

during the rooting process, i managed to see some kind of error complaining about busybox in the console. in the end the root worked but after i was done i installed busybox from the play store just to be safe.

in the build.prop i obviously changed the "en" and "EN" to my country codes. i also found the characters on android very small so i adjusted the ro.sf.lcd_density=160 to ro.sf.lcd_density=188 (which is the actual DPI value of the screen) and it looks much better to me.

i had no problem in getting the play store working with this method, however, be wary that clearing the data of google play services is tricky cause there is no button in the uninstall/deactivate screen, it is hidden further under another button (can't remember which one now) that will open something like "google play services preferences" or something like that.

Fifth Step: installing Xposed

this one is quite easy, i followed the instructions for installing Xposed for the x98:

install terminal emulator

install the xposed framework installer 2.61 apk (but DONT launch it yet)

open terminal emulator, insert the following commands:

su
cd /
cd /data/data/de.robv.android.xposed.installer
mkdir conf
cd conf
echo 0x98 > ./jit_reset_offset

close terminal emulator

open ES file explorer, go to /data/data/de.robv.android.xposed.installer

change the conf directory permissions to rwx rwx rwx (select the directory then menu key -> properties)

then go into conf and set the jit_reset_offset permissions to rwx r r

reboot the tablet

now open xposed installer and install xposed, then reboot

Sixth Step: Installing Windows

to begin, i burned the win 8.1 with bing x86 english ISO to a DVD (i guess you can use it to make a bootable USB drive too but it's kinda tricky to get it right for booting 32 bit UEFI)

next up, i attached a usb hub with keyboard, mouse and a USB DVD drive to the OTG port

the tablet recognized the windows setup and prompted the dual boot screen with android on the left and a small square with the windows logo on the right, which booted the DVD when selected

from then on it's just a normal Windows installation. just be sure to select Custom install and select the unallocated space on the drive as destination

after the setup finished, i unzipped the driver package to a USB drive and connected it to the tablet.

then i went into device management and right clicked on each of the unknown devices there, selected "update driver software" , then "browse my computer for driver software" and pointed it to the folder containing all the unzipped drivers.

do the same with the video card that will not be an unknown device, rather a "microsoft standard video card" and for the new unknown isp device that will appear (it's the intel signal processor thingy)

after all unkown devices are gone, reboot

go back into the device manager, right click on the root entry (the computer) and select "add legacy hardware"

click next, then select manually (2nd option)

from the list select Sensors, click next

click the Have Disk button, and point it to the kionix sensor fusion device driver, finish the wizard

now the rotation works but it's inverted. to fix it, import the attached reg file into the registry

add another legacy hardware manually, this time select microsoft from the left menu and select "windows location provider"

now go into the disk manager and right click on every one of the small android partitions and select the option to remove the assigned drive letter

...work in progress...