Monday, May 26, 2014

Asus Transformer Book T300LA Trusted Platform Module (TPM) confirmation

You are asked to confirm a change in the TPM configuration on an Asus Transformer Book T300LA laptop with a message similar to:
"A configuration change was requested to clear this computer's TPM (Trusted Platform Module)
WARNING: Clearing erases information stored on the TPM. You will lose all created keys and access to data encrypted by those keys.
Press F12 to clear the TPM
Press ESC to reject this change request and continue"

Unfortunately, the keyboard does not seem to respond, the F12 and ESC keys are not working. USB keyboards are also useless.
Turning the device off and on also comes back to this message. There is no way to get rid of this message without confirming or rejecting it.

The root cause of this is that the TPM uses a special restricted startup mode to display this message in which all non-essential devices are disabled. For the Asus T300LA this includes the USB ports, and the wireless keyboard.

Force the laptop to enable the USB ports and keyboard on startup by using the direct USB booting method (Power button + Volume Up key combination).

1. Turn off the device
2. Press the Volume Up button and keep it pressed until the TPM message appears
3. Turn on the device

A small hourglass will appear in the center of the screen, and the text will probably look a bit larger than usual.
The standard wireless keyboard should now be enabled, and you can confirm or reject the TPM message with the F12 or ESC keys.

Note: For this to work you might need to be running BIOS version 206 or newer