Volume = Up/down menu
Power = Enter
** Plug in your Power Cord, its required! **
** First make sure to backup all your multimedia files (and apps if you want) **
1) download the firmware here: http://update.archos.com/8/gen8/gen8_2. ... d_gen8.aos
2) shutdown your device by tapping power, then selecting power down or holding the power for 5-10 seconds
3) hold the volume down and power button until you get the Archos splash screen
4) Select Format System --> Reformat Device--> Select "I Understand"
5) Once format is complete, you'll then you'll be in USB firmware Recovery mode (do not press OK yet)
6) Your device should be automatically be mounted (A70S internal drive) in Windows (Linux too I'm sure)
7) Copy your downloaded 'aos' file from step 1 into the root of the 'Axxx' named drive letter

9) Firmware update begins
That's it, you now have a super fresh restore of your system! You can format/install previous firmwares too. The 'aos' file is deleted automatically once the update is completed.
Use this at your own risk. It's pretty straight forward, but if you reformat and cant for whatever reason copy the 'aos' file to your internal memory, you've pretty much bricked your device and will need Archos support more then likely.
There are also some non-extreme options, such as 'reset android' in there as well.
Rumor has it that your can't go back to prior firmware, but I don't see why not if you do reformat, but I haven't tried personally.
1.0.84 firmware (2.1 Eclair)
http://update.archos.com/8/gen8/gen8_1. ... d_gen8.aos
3rd party apps:
ftp://support.archos.com/A70%20HDD%20contents.zip
Have fun!