You install Windows Vista before you update the basic input/output system (BIOS) to a Trusted Computing Group (TCG)-compliant version. If you do this, the Trusted Platform Module (TPM) 1.2 device driver (Tpm.sys) is not loaded. Additionally, a yellow exclamation point (!) appears next to the TPM 1.2 device in Device Manager.

Note: The TPM 1.2 device remains in this state even after you update the BIOS to a TCG-compliant version.