When you convert to NTFS, all files and directories default to Everyone - Full Control.
When you format a drive as NTFS and install Windows NT, the following default permissions apply (assuming drive C:):
C:\
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
System - Full Control
C:\Msapps and <subdirectories>
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\Program Files and <subdirectories>
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\Temp
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
System - Full Control
C:\Users
Administrators - Special (RWXD)
Everyone - List(RX)
System - Full Control
C:\Users\Default
Creator/Owner - Full Control
Everyone - Special (RWX)
System - Full Control
C:\Win32app
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Read(RX)
Server Operators - Full Control
System - Full Control
C:\%SystemRoot%
Administrators- Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\%SystemRoot%\Config
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\%SystemRoot%\Cookies
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\%SystemRoot%\Cursors
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\%SystemRoot%\Desktop
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\%SystemRoot%\Fonts
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\%SystemRoot%\Help
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\%SystemRoot%\History
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\%SystemRoot%\Inf
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\%SystemRoot%\Java and <subdirectories>
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\%SystemRoot%\Media
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\%SystemRoot%\Nwspool
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\%SystemRoot%\Profiles
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\%SystemRoot%\profiles\Administrators
Administrators - Full Control
System - Full Control
C:\%SystemRoot%\profiles\All Users and <subdirectories>
Administrators - Full Control
Everyone - Read
System - Full Control
C:\%SystemRoot%\profiles\Default User and <subdirectories>
Administrators - Full Control
Everyone - Read
System - Full Control
C:\%SystemRoot%\Profiles\<username> and <subdirectories>
Administrators - Full Control
<username> - Full Control
System - Full Control
C:\%SystemRoot%\Repair
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Read
Server Operators - Full Control
System - Full Control
C:\%SystemRoot%\Shellnew
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\%SystemRoot%\System
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\%SystemRoot%\System32
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\%SystemRoot%\System32\Cache
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\%SystemRoot%\System32\Config
Administrators - Full Control
Creator/Owner - Full Control
Everyone - List
Server Operators - List
System - Full Control
C:\%SystemRoot%\System32\Dhcp
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Read(RX)
Server Operators - Full Control
System - Full Control
C:\%SystemRoot%\System32\Drivers and <subdirectories>
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Read(RX)
Server Operators - Full Control
System - Full Control
C:\%SystemRoot%\System32\Inetsrv and <subdirectories>
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\%SystemRoot%\System32\Lls
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\%SystemRoot%\System32\Logfiles
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\%SystemRoot%\System32\Netmon and <subdirectories>
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\%SystemRoot%\System32\Os2 and <subdirectories>
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\%SystemRoot%\System32\Ras
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change(RWXD)
Server Operators - Full Control
System - Full Control
C:\%SystemRoot%\System32\Repl
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Read(RX)
Server Operators - Full Control
System - Full Control
C:\%SystemRoot%\System32\Repl\Export and <subdirectories>
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Read(RX)
Replicator- Change(RWXD)
Server Operators - Change(RWXD)
System - Full Control
C:\%SystemRoot%\System32\repl\import and <subdirectories>
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Read(RX)
Replicator- Change(RWXD)
Server Operators - Change(RWXD)
System - Full Control
C:\%SystemRoot%\System32\Spool and <subdirectories>
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Read(RX)
Print Operators- Full Control
Server Operators - Full Control
System - Full Control
C:\%SystemRoot%\System32\Viewers
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
C:\%SystemRoot%\System32\Spool\Wins
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change(RWXD)
Server Operators - Change(RWXD)
System - Full Control
C:\%SystemRoot%\Temporary Internet Files and <subdirectories>
Administrators- Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
Other directories
Administrators - Full Control
Creator/Owner - Full Control
Everyone - Change
Server Operators - Change
System - Full Control
