Ensure that there is sufficient contiguous space to install FDE.
Perform the following and try to install the Endpoint Encryption FDE agent again once enough space is avaiable:
- Disable System Protection. Refer to the Windows article: How to Turn On or Off System Protection for Drives in Windows 10
- Disable Kernel Memory Dump. Refer to the Microsoft article: Enabling a Kernel-Mode Dump File.
Disable both Page Files and Hibernation. Refer to the following guides:
- Install the Endpoint Encryption FDE agent.