Getting the Username from the HKEY_USERS values

By searching for my userid in the registry, I found

HKEY_CURRENT_USER\Volatile Environment\Username

It is possible to query this information from WMI. The following command will output a table with a row for every user along with the SID for each user.

wmic useraccount get name,sid

You can also export this information to CSV:

wmic useraccount get name,sid /format:csv > output.csv

I have used this on Vista and 7. For more information see WMIC - Take Command-line Control over WMI.

1. Open Reg HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList\

2. make a loop to get all subkeys

3. the subkeys you are interested with are those started with [S-1-5-21-] which means user (see key name [ProfileImagePath] they are always started with a path c:\Users)

4. Those starting with [S-1-5-21-12] are all local users

5. Those starting with [S-1-5-21-13] are all network users [if joined to Domained network] that are previously logged on the machine.

If you look at either of the following keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\hivelist

You can find a list of the SIDs there with various values, including where their "home paths" which includes their usernames.

I'm not sure how dependable this is and I wouldn't recommend messing about with this unless you're really sure what you're doing.