What is the default value of NoDriveTypeAutoRun in Windows 10 and Windows 11 when the registry entry does not exist?

Question

Hello,

I’m checking the Windows registry setting for NoDriveTypeAutoRun under HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer.

I would like to confirm what the default value is when this registry entry does not exist.

Some online sources mention 0x91, while others mention 0x95. Could Microsoft please clarify the official default value for Windows 10 and Windows 11?

Thank you! 🙏

Answer 1

Hello,

If the registry value does not exist, Windows 10 and Windows 11 default to 0x91 for NoDriveTypeAutoRun. That value disables AutoRun for unknown and network drive types, and Windows will use it implicitly when neither HKLM nor HKCU defines the setting.

Microsoft's docs describe the key and its bit flags, and reference 0x91 as the default when you need to recreate it.

Why some sources say 0x95: before the Windows 7 security hardening, admins often set 0x95 to also flip the Removable-drive bit. Since Windows 7, AutoRun from non-optical removable media is blocked regardless of this registry value, and that behavior continues in Windows 10 and 11.

If you want Windows to use its built-in defaults, simply leave NoDriveTypeAutoRun absent in both HKLM and HKCU. If you must set it explicitly, use 0x00000091.For the official description of the key and where it lives, see Microsoft Learn's AutoRun registry reference.

Answer 2

The default value of the NoDriveTypeAutoRun registry entry in Windows 10 and Windows 11 when the entry does not exist is 0x00000091 (145 in decimal).

This value corresponds to auto-running disabled for removable drives, which includes USB drives, CD/DVDs, and other types of external storage, while still allowing auto-run for network drives. This setting effectively prevents unwanted automatic execution of programs from these types of drives, which helps to prevent malware or unwanted programs from running automatically.

If the NoDriveTypeAutoRun key is missing, the system will use this default value, which is considered the security-recommended behavior.

To summarize:

Default value (if the entry doesn’t exist): 0x91 (145 decimal)

It corresponds to: AutoRun disabled for external/removable drives, enabled for network drives

You can always modify this value if you want to customize auto-run behavior for different drive types. Just be sure to back up your registry first!