My assumption is that a BIOS update, while having a TPM activated, would render the computer unusable so that I could trash it unless I can revert the changes to the BIOS.
1) Is it possible to deactivate the TPM, for example in order to install a Bios update, and then activate it again?
2) If it is possible to deactivate a TPM (only from within a running OS I assume), then is the following conclusion true? The TPM only protects against attackers who do not have access to the running operating system (= operating system after it has booted).