Start up the computer with an option that will ignore signatures, and it should work. If you cannot do it in DOS prompt(it didn't work for me), you can do it during windows start up. Press F8 before windows logo comes up, and you will get start up options, and there should be one regarding signatures. Once the OS starts up ignoring signatures, the drivers will be functional that you previously installed, and that yellow triangle will be gone.
When I boot into regarding signatures mode I see my soundcards in system (and all OK), but I see no soundcards in Sound manager.