I was reading about this issue. Please refer Gizmo001 answer on social technet forum.
Import the certificates prior to install
Follow these steps:
1. install the software once manually by confirming that the unsigned drivers shall be used
2. go to %windir%\inf and search for the latest OEM??.INF file; open it (notepad) and verify by its contents that this is the driver you wish to install automatically next time
3. go to %windir%\system32\catroot{any ID}\OEM??.CAT (<- same number as in step 2); right click on this file, select properties, go to "Digital Signatures" tab, mark the certificate, click on details
4. on the next window click "Show Certificate"
5. on the next window open the "Details" tab and click "Save to File..."
6. collect this/all certificates
7. deploy these certificates
7.1 either in a batch /cmd script using "certutil.exe -f -addstore "TrustedPublisher" "MYFILE.cer" prior to setup
7.2 or by Group Policies (computer \ Policies \ Windows \ Security \ Public Key Policies \ add your files here )
8. run your setup just the way you wanted