Hi @xianhua 李 ,
There are some possibilities that may cause Bitlocker Drive Encryption not to start.
We can first confirm that whether the client agent is installed in Programs and Features.
If it is, please check the following two points, they may cause BitLocker Drive Encryption doesn't start.
- Is there any remote desktop protocol connection is active? If there is, close them all.
- Sign in the client with a domain user account but not a local user account.
If we sign in with a local user account, BitLocker Drive Encryption doesn't start.
For more details, we can use this article as a reference:
https://learn.microsoft.com/en-us/mem/configmgr/protect/deploy-use/bitlocker/deploy-management-agent#deploy-a-policy
Hope the above information is helpful to you.
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