[Transformer TF300T Android Development] anduzer:
For users who are in the same situation and found some of the information here a bit confusing :confused: and (mistakenly upgraded to .26 or received .26 from the beginning). This method - guide works: :) . I was going to create a new Thread with this guide I wrote, but today another user create it the guide/Thread by using part of this info.

a) I downgraded from .26 firmware to .17 by doing the following:

ONE CLICK Downgrade, using Wolf's method and root tool (thanks to viperboy)

http://xdaforums.com/showpost.php?p=25508554&postcount=52

Just put the BLOB file of FW (aprox 750mb+ file with no extension, extract it from the zip)

http://dl.dropbox.com/u/53726414/US_epaduser9_4_3_17UpdateLauncher.zip

(Asus pulled the files off the web site so I got the BLOB file from http://xdaforums.com/showthread.php?t=1642614)

Then put the BLOB file on the root of your tf300 internal memory (I also placed it a copy of it in the root root of SD card - just in case), then make sure that usb debugging is enabled, also make sure you have the asus drivers installed in your windows machine: I got the drivers by installing:

ASUS Pad PC Suite (PC version V1.0.41)

from http://support.asus.com/Download.aspx?SLanguage=en&m=ASUS+Transformer+Pad+TF300T&p=20&s=16

Then you can run option 1 on the modded vipermods tool (via windows machine) : viperMOD Primer Tool v4.5 - Modded by bpear_v3.exe

exe from :

Download:

https://docs.google.com/uc?id=0B8gHy...xport=download

http://www.mediafire.com/?7j79e3b3mf6hh7l

http://d-h.st/KrP

b) Then apply ROOT to .17 FW with SparkyRoot

It is a one click root app:

SparkyRoot.apk - (1.09 MB, 9403 views)

from

http://xdaforums.com/showthread.php?t=1526487

c) Once root is done, get Voodoo root keeper app from android/play market and save full root.

d) Update the firmware to .26 via OTA/wifi works perfectly. Then restore root with Voodoo root keeper app, and install your apps: Droidwall, Titanium Backup, Rom Manager etc.. Thanks for all the help from other devs and tips from users :)

FYI: This note created by demandarin is very important for this process:

VERY IMPORTANT, ACTUALLY MOST IMPORTANT THING TO DO:

As soon as you're rooted, get Voodoo OTA rootkeeper. its free from the marketplace. then open that app up and Save and backup your root. REPEAT, SAVE & BACKUP YOUR ROOT.

you will kick yourself in da a$$ if you don't..lol. then now you can update to the latest firmware for 300, which is .26 or whatever. Once you update, you will initially lose root.

but no worries. you just open up the voodoo app and restore your root. Now you are rooted again on latest firmware. you will use this method from now one to restore root

after a firmware update. there has already been confirmation of a 300 owner rooting on.17, then using voodoo to save/backup his root, then update to .26.

then using voodoo to restore root. now he is rooted on latest .26 firmware for 300.

you will be sorry if you don't use voodoo to save your root. even if you don't immediately update afterwards. only reason root is working on 300 is because its the ones

with .17 firmware. there is no root method currently available or even in developement yet, as far as we know, That will work on .26 or higher.

SO BACKUP N SAVE YOUR ROOT FILE WITH VOODOO OTA keeper. do it immediately, don't wait. I've seen too many people gripe and cry about losing root

because they forgot to backup n save root. now they are stuck on latest firmware and can't root. that was at first but now prime has downgrade methods

that seem to work for some. but this hasn't been confirmed to work on 300 though since there is no blob file posted for .17.