Can you remember exactly what it said - "No Encryption Present" is not one of the standard messages.
But, it would only report on the presence of an MBR - if the drive was encrypted as a 2nd drive, the disk info will be in the partition gap, you'd have to go looking for it if it got left behind by a failed/aborted remove historically.
Killdisk should zero everything though. If it works, then most likely that was the root problem.
What version of EEPC is installed on the client? Here's some things to look at:
Hope that gets you started.
not connected as external drive. has the same drive letter assigned as what is denoted in the policy
not been active with EEPC
I even deleted and formatted the drive and tried adding back. Still not working. this is just one of 50 laptops that this has ever happened with.
Formatted as a gpd drive? Set to dynamic?
A screen shot comparing disk information from disk manager between a working and non working machine might shed some light.