Try the following:
1) Boot the machine into windows (use administrator recovery, then machine recovery)
2) Once the machine has loaded windows go to ePO and select the system and remove all users.
3) Wake up agents and check to enforce policy
4) Once the policy enforcement has been completed then go back to ePO and add users again.
5) Wake up agents and check to enforce policy
6) Once the policy enforcement has been completed reboot the machine and logon to Preboot.
If the above fails then use the stand alone EETech and perform an emergency boot. Then once windows have been loaded then wake up agents and enforce policies. This will rebuild the PBFS.