hkey_users\s-1-5-21-_classes - SERP Analysis

https://learn.microsoft.com/en-us/answers/questions/417373/what-is-user-starting-s-1-5-21-1687699058

https://answers.microsoft.com/en-us/windows/forum/all/found-in-registry-editor-hkeyuserss-1-5-21/d100dfd7-18d8-4fa4-91fd-d06386620c07

https://stackoverflow.com/questions/2919286/getting-the-username-from-the-hkey-users-values

https://system32.eventsentry.com/codes/field/Well-known%20Security%20Identifiers%20(SIDs)

https://www.reddit.com/r/Windows11/comments/zyrerr/registry_what_exactly_is_hkey_users/

https://www.tenforums.com/general-support/196612-cant-access-classes-subkey-after-loading-users-hive-registry.html

https://github.com/notepad-plus-plus/notepad-plus-plus/issues/13871

https://relyonsoft.in/techsupport/error-1401-could-not-create-key-hkey_userss-1-5-21softwareclasses-verify-that-you-have-sufficient-access-to-that-key/

https://superuser.com/questions/1527049/windows-10-3-separate-machines-showing-account-unknown-s-1-5-21-1000

https://github.com/Mr-Un1k0d3r/ATP-PowerShell-Scripts/blob/main/a391f42c-7e1a-4611-8494-1817d2420e09.ps1

https://www.bleepingcomputer.com/forums/t/453159/odd-registry-entry/

https://msfn.org/board/topic/94998-whos-who-in-the-registry/

https://www.pcreview.co.uk/threads/why-do-i-have-multiple-hkey_users-but-only-one-account.2664051/