Driver signing can no longer be disabled on Vista. Everything is hard coded to Warn. There is no more Ignore or Block policy available in the product code.
We cannot suppress this "Warning" dialog box. The only way for us to avoid it would be to sign the driver package. On x86 unsigneddrivers will load, but you will always see the warning. However, once the driver loads, it becomes part of the driver storage so, uninstalling and reinstalling the unsigned driver should not produce the Warning dialog again.
Please use Makecert that’s included with the WDK to sign the driver: http://www.microsoft.com/whdc/devtools/WDK/AboutWDK.mspx
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