When a user logs into a Windows machine, the operating system assigns a unique SID to their session. This SID is used to identify the user and manage their access to system resources. If the user's SID changes (e.g., due to a domain change or a user account modification), the sidchg key is updated to reflect the new SID.
ALTUSER userid NOSIDCHG
The system will log out and restart. Do not interrupt this process, as it involves deep system modifications. Key Command Options for Licensing sidchg key