Configure Autorun for different drives using policies

Windows is by default configured to poll all devices every second to check if the media has changed since last poll. If the media has changed then it checks if a file named Autorun.inf is placed in the root.

One can configure what drive-letters shouldn't be checked for Autorun.inf. Each bit corresponds to a driveletter.

BitValue(Dec)Value(Hex)Letter
110x00000001A:
220x00000002B:
340x00000004C:
480x00000008D:
5160x00000010E:
etc.etc.etc.etc.

[HKEY_CURRENT_USER \Software \Microsoft \Windows \CurrentVersion \Policies \Explorer]
NoDriveAutoRun = 0x00000005 (DWORD)

Disables the checking for Autorun.inf on A: + C:

One can configure what drive-types shouldn't be checked for Autorun.inf. Each bit corresponds to a drivetype.

BitValue(Dec)Value(Hex)Type
110x00000001DRIVE_UNKNOWN
220x00000002DRIVE_NO_ROOT_DIR
340x00000004DRIVE_REMOVABLE (Floppy etc.)
480x00000008DRIVE_FIXED (HDD etc.)
5160x00000010DRIVE_REMOTE (Network etc.)
6320x00000020DRIVE_CDROM
7640x00000040DRIVE_RAMDISK
81280x00000080Unspecified Reserved Type (Should always be set)

[HKEY_CURRENT_USER \Software \Microsoft \Windows \CurrentVersion \Policies \Explorer]
NoDriveTypeAutoRun = 0x00000095 (WinNT+ DWORD)
NoDriveTypeAutoRun = 95 00 00 00 (Win9x BINARY)

Disables the checking for the file Autorun.inf on "Unspecified Reserved Type" + DRIVE_REMOTE + DRIVE_REMOVABLE + DRIVE_UNKNOWN

Note if disabling autorun for all devices (0x000000FF) then it will also disable the Vista Hotstart feature.

Note there is a little confusion about autorun on USB drives, which have caused the creation of software like APO Usb Autorun:

Autorun.inf files are not supported under Microsoft Windows XP for drives that return DRIVE_REMOVABLE from GetDriveType. MSDN

The Autorun capabilities are restricted to CD-ROM drives and fixed disk drives. If you need to make a USB storage device perform Autorun, the device must not be marked as a removable media device. USB FAQ

The action key is only used in Microsoft Windows XP Service Pack 2 (SP2) or later. It is only supported for drives of type DRIVE_REMOVABLE and DRIVE_FIXED. In the case of DRIVE_REMOVABLE, the action key is required. MSDN

Note these policies only work on media which are able to contain an Autorun.inf file. Media like Audio CDs will not be affected by the setting of these policies.

Note if one don't want to enable autorun for a single CD-ROM, then instead just hold down the SHIFT key while inserting the CD-ROM.

Note if having Autorun.inf checking enabled for floppy drives, then it might at random access the floppy drive and grind for a long time searching for the Autorun.inf. This grinding can also happen if accidentally having a shortcut pointing to a file placed on A: or B: drive.

More Info MS KB136214
More Info MS KB177880
More Info MS KB967715

To disable the polling of CD-ROM/DVD devices:

Related Win9x/Me : Configure Autorun for the CD-ROM drive
Related WinNT/2k/Xp : Configure Autorun for the CD-ROM drives

Credits ashzfall.com

Updated: 12 December 2012

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