This post explains why BitLocker might be missing or not showing in Control Panel on your Windows 11/10 and the steps you can take to resolve the issue.

Fix BitLocker error E_FVE_TPM_NOT_DETECTED, The booting system doesn't have or doesn't detect a TPM in Windows 11/10.

In such cases, you see the “Windows cannot be installed on this hard disk space. BitLocker Drive Encryption is enabled on the selected partition.