Sometimes, the command fails to execute properly. The most frequent issue is Error 0xC004FE00, which suggests the system has already exceeded its rearm limit. Another common hurdle is the "Access Denied" error, which happens if the Command Prompt was not opened with administrative rights.
You can also use additional options with slmgr rearm to prepare a specific feature: slmgr rearm windows 10
slmgr rearm
