Software Deployment

Hi all,

I am trying to install an application onto a Windows 7 OS.
There are 2 Custom Actions within the msi that install 2 Device Drivers.

When one of these Custom Actions is run windows throws up a "Windows Security" message.
saying "Windows can't verify the publisher of this driver software" -
Don't Install this driver software OR Install this driver software anyway.

I don't want this error message to appear.
The driver is a Texas Insturments driver and according to the Vendor it is a verified driver but just not be Microsoft.
I therefore want to change the driver signing option to Ignore and not Warn but can't seem to do this in Windows 7.

I have found on Google that if you do the following -
HKCU\Software\Microsoft\Driver Signing\Policy to 0 and HKLM\Software\Microsoft\Driver Signing\Policy to 0 this should Ignore. I tried this but it didn't work.

I also tried using bcdedit.exe with the following command lines to no avail -

bcdedit.exe -set loadoptions DDISABLE_INTEGRITY_CHECKS
bcdedit.exe -set TESTSIGNING ON

Anyone know how to get rid of this dialog box so I can make it a silent install.