The General Purpose Key (GPK) is used to encrypt part of the registry for domain users. However, during the boot process, in rare cases, it might become corrupted and fail to unseal. If so, the following errors display in the CMGShield.log file on the client computer:
[12.06.13 07:56:09:622 GeneralPurposeK: 268] GPK - Failure while unsealing data [error = 0xd]