I am trying to find a unique windows value that I can use for basing a product key on. I have been fetching the machine ID on XP and Vista from the registry and that works fine. However, I've just been working with Windows 7 und alles kaput.

The following works fine with XP and Vista:

my $Machine = Win32::TieRegistry->new(
                "LMachine/Software/Microsoft/MSLicensing/HardwareID",
                { Access=>"KEY_READ", Delimiter => '/', },
            ) ;
[download]

But on Windows 7, $Machine is undefined. I've tried every conceivable permutation that I can imagine ... and then some. Even running that snippet as an administrator. I can get and set values under HKEY_CURRENT_USER in Win7 fine. I just can't pull in values from HKEY_LOCAL_MACHINE.

It sorta looks like I need to brush up on the Win7 administration of rights and privileges. Any suggestions on what I need to be looking into would be welcome.

Maybe my goal is wrong. Does anyone know of any other unique identifier for Windows machines?

Thanks.