The Operating System has two sets of Registry Keys for Driver Signing. Even with one disabled in Windows 2003 x64 (HKLM>Software>Microsoft>Driver Signing) there is a secondary key that can still leave Driver Signing Warnings set to enabled. This is by design, as per Microsoft's Knowledge Base article (http://support.microsoft.com/kb/298503).
Because of this, the GAB and LLT drivers (even though they are signed and even when running the SYMCCERT or Trusted Certificate option during installation) will still prompt a user warning.
To resolve this issue and allow for an unprompted installation, please perform the following steps:
- Verify there is not a Group Policy being pushed to the server which may overwrite settings
- Verify the user account operating the installation has Local Administrator priviliges, including installation of Signed / Unsigned Drivers
- Verify that under Control Panel > Settings> Hardware> Driver Signing, the option is set to Ignore
- Open the Registry Editor (Start > Run > Regedit)
- Browse to HKEY_LOCAL_MACHINE > Software > Microsoft
- Highlight the Non Driver Signing key located here
- Change the value to be Zero (0)
- Restart installation and verify successful completion without Driver Signing Prompt.