Microsoft – TPM Base Services
The Trusted Platform Module (TPM) Base Services (TBS) is a software component that allows the Windows operating system and applications to use services provided by the TPM.
Because multiple applications on a computer share a single TPM hardware component and TPM driver, the TBS virtualizes certain limited TPM resources. The TBS uses priorities specified by calling applications to cooperatively schedule TPM access. For more information, please visit http://technet.microsoft.com/en-us/library/cc734063.aspx