If you want to prevent standard users from changing your BitLocker drive encryption password/PIN, you can deploy the relevant Enable/Disable GPO setting for this.

First off, I'm running Windows 8.1 and I don't have a TPM. I know all about going under the local Group Policy and disabling the TPM requirement. That's fine, I understand that aspect of it. Where ...

The BitLocker Windows security feature mitigates the risk of data theft or information exposure from lost, stolen, or inappropriately decommissioned devices by encrypting the storage drives.