A common reason why you might want to find the security identifier (SID) for a user’s account in Windows is to determine which key under HKEY_USERS in the Windows Registry to look for user-specific registry data. Matching SIDs to usernames is easy with the wmic command—available from the Command Prompt in most versions of Windows.
Follow these easy steps to display a table of usernames and their corresponding SIDs. It’ll probably only take a minute, maybe less, to find a user’s SID in Windows via WMIC:
See How to Find a User’s SID in the Registry further down the page for instructions on matching a username to an SID via information in the Windows Registry, an alternative method to using WMIC. The wmic command didn’t exist before Windows XP, so you’ll have to use the registry method in those older versions of Windows.
wmic useraccount get name,sid
…and then press Enter.wmic useraccount where name="USER" get sid
Now that you’re confident a particular user name corresponds to a particular SID, you can make whatever changes you need to in the registry or do whatever else you needed this information for.
If you happen to have a case where you need to find the user name but all you have is the security identifier, you can “reverse” the command like this (just replace this SID with the one in question):
wmic useraccount where sid="S-1-5-21-992878714-4041223874-2616370337-1001" get name
…to get a result like this:
Name
jonfi
You can also determine a user’s SID by looking through the ProfileImagePath values in each S-1-5-21 prefixed SID listed under this key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList
The ProfileImagePath value within each SID-named registry key lists the profile directory, which includes the username.
For example, the value under the S-1-5-21-992878714-4041223874-2616370337-1001 key on the computer you see above is C:\Users\jonfi, so we know that’s the SID for that user.