system partition

I have noticed on some of my machines that the system partition created by the fde process is visible in windows explorer with a drive letter assigned. My fde policy encrypts all local drives. On 1 machine the recovery image was also assigned a drive letter and the policy tried to encrypt it. My questions are
1. how do I tell if the drive is encypted
2. can I adjust the policy to just encrypt the c drive without decrypting the devices
3. is there a report I can run to see which devices have a drive letter assigned to any partitions other than the o/s
4. if the drive is encypted how do I decrypt