How to Associate a Username with a Security Identifier (SID)

 Sometimes, you need to know what the security identifier (SID) is for a specific user on the system. To see what the SID is for a specific user, perform the steps below. 

WARNING: Using Registry Editor incorrectly can cause serious, system-wide problems that may require you to reinstall Windows NT to correct them. Microsoft cannot guarantee that any problems resulting from the use of Registry Editor can be solved. Use this tool at your own risk.

1.     Open Registry Editor and navigate to:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion \ProfileList

2.     Under the ProfileList key, you will see the SIDs. By selecting each one individually, you can look at the value entry and see what user name is associated with that particular SID.