How to Sign PDA Cab File

I need someone to show me how to correctly sign a PocketPC Cab file, so when I install that cab file on PDA, it does not prompt "Unknown publisher" warning message. What I have tried: use signtool from Visual studio and sampl pfx file, but I still see the "Unknown publisher" when I install the cab file. So I need someone to show me step by step instructions to sign the cab file correctly and avoid such warning message during cab install on PocketPC