JSI Tip 2023. How did HOTFIX Q147222 get in my registry, I didn't apply this fix?

When you apply Service Pack 4 for Windows NT 4.0, it automatically posts Q14722 to:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Hotfix

This HOTFIX covers Exchange 5.5 and IIS 4.0, and it's inclusion is part of SP4.