Dell XPS Consumer Information page 12

Dell XPS Notebook Reimage "How-To" Guide
TPM Security:
These options enable and configure the Trusted Platform Module (TPM). If TPM is to be deployed,
TPM must be enabled in the BIOS Setup program
2. Security  TPM Security

TPM Security:

Disabled: The BIOS will not turn on the TPM during POST.
The TPM will be non-functional and invisible to the Operating System

Enabled(Default): The BIOS will turn the TPM during POST so that it can be
used by the Operating System

PPI Bypass for Enable Commands = This option controls the TPM Physical Presence
Interface(PPI). When enabled, this setting will allow the OS to skip BIOS PPI user prompts
when issuing TPM PPI enable and activate commands.

PPI Bypass for disable Commands = This option controls the TPM Physical Presence
Interface(PPI). When enabled, this setting will allow the OS to skip BIOS PPI user prompts
when issuing TPM PPI disable and deactivate commands.

Clear = The BIOS clears the information stored in the TPM