Disabling monitor speakers with HDMI connection

I just received a 24-inch HP monitor and am dual-screening with another monitor. In order to be able to use both, I connect the HP using HDMI and the other using VGA. Unfortunately, I am getting audio only from the 24-inch monitor as opposed to my regular speakers, which are plugged into a dock, into which my HP notebook is connected. I tried to disable the HDMI monitor speakers through control panel but sound still does not come from the speakers. Please let me know if there is a simple solution to this and that I am just being an idiot (I sure hope so...).

I am using Vista 64-bit if that is relevant at all.

Thank you!

Okay, here's what worked for me in Vista 64 bit. You need to make sure your laptop's speakers are the default speakers.

Shut down all programs that play sound. Make sure you have your external monitor connected to the laptop.

Right click on your desktop, and select "Personalize."

Select "Sounds."

Select "Playback" tab.

Click on the set of speakers you'd like the music to come out of. Then select "Set Default." When you see a green circle with a check mark appear over the laptop's speakers, you're done.

Worked for me, anyhow.