Get Microsoft's TweakUI powertoy and use it to disable autorun. In
TweakUI, go to the following tree node:
My Computer
|___ AutoPlay
|___ Types
Although it says it is an auto-play option (which is used to determine
what handler gets used for what content on a CD/DVD drive), the Types
settings modify the following auto-run registry key:
Key: HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
Item: NoDriveTypeAutoRun
Since that is under the HKEY_CURRENT_USER hive, changes the settings are
effected only under your account. You would have to logon under each
account to use TweakUI (or gpedit) to change the setting under each
account, or edit the HKEY_USERS hive to make changes on all accounts
without having to log into each account.
If you want to use the group policy editor (gpedit.msc) then go to its
following tree node:
Local Computer Policy
|___ Computer Configuration
|___ Administrative Templates
|___ System
You can disable auto-play (aka auto-run) there. You'll probably want to
disable it on all drives. Gpedit lets you disable/enable auto-play on
all drives or just on CD/DVD drives. Selecting all drives results in
using a hex value of FF in the NoDriveTypeAutoRun registry item.
TweakUI doesn't let you disable auto-play on all drives (because the
setting is rather meaningless) and instead offers to disable/enable
auto-play on CD/DVD drives or removable drives (e.g., USB thumb drives)
or both. That results in setting NoDriveTypeAutoRun to B5 hex.
This registry value is a bit mask. Convert the hex value to binary and
each 1 in that value represents where auto-play is disabled (you are
enabling the disable).
http://support.microsoft.com/kb/967715 for info
on what each bit means in the mask.
TweakUI: Turn off auto-play on CD/DVD drives and removable drives
Value: B5 hex = 1011 0101 binary
Disables: bit 0 = drives of unknown type
2 = removable drives
4 = network drives
5 = CD-ROM drives
7 = reserved
gpedit: Turn off auto-play on all drives
Value: FF hex = 1111 1111 binary
bit 0 = drives of unknown type
1 = (reserved)
2 = removable drives
3 = fixed drives
4 = network drives
5 = CD-ROM drives
6 = RAM disks
7 = (reserved)
I don't see when auto-play would be applicable to fixed or RAM disks so
the settings used by TweakUI are sufficient. gpedit just disables (sets
the disable) all of them when you select all drives.
As to you not seeing the System subnode in gpedit's tree, are you logged
under an administrator account when you use gpedit? Are you logged
under a local admin account or under a domain account (in which you've
been granted some admin rights on your host)?