Did you try the second step (second paragraph in my last post)? If so, how was the audio mixer configured in control panel? Was use the device selected? Check on that again and let me know how it's configured.
If you've had problems with this card in the past is it possibly a driver related issue? Find out the name of the manufacturer of the card and then download a Windows ME driver for it, maybe they've updated the file. After you've downloaded the driver go into device manager and update the driver for the sound card.
If you can't find the name of the manufacturer then just uninstall the card in device manager and then reboot. Upon reboot the card will be reinstalled (providing there is nothing wrong with the driver) and all settings will be restored to default, you'll have the speaker icon and the card will be set up as the default audio device.
With or without that sound card working the RPC-1 should still function, it has nothing to do with the speaker icon in the system tray. Are you getting any output from the RPC-1? What are you using it with? I'm assuming the VM-3100. I can tell you for sure that if you're playing a CD on your PC it will not be output to the RPC-1. You'd have to take the output of the sound card and connect it to an input channel on the VM3100 in order to hear the CD. This is the same for any Windows based media players or editors with the exception of Logic RPC, providing you are using the VM3100.
Just as a test import an audio file into Logic and see if you get any output from the VM3100. If not, try raising the BUS 1/2 fader and/or the master fader. You should now hear the audio file played back through the RPC-1 card and the VM3100.
Hope this helps.
Stray