Windows Vista Speakers now wont work

[Unregistered]

My mom has an HP with Vista, and some external speakers that I dont know what they are. Everything was working fine -- speakers and all, untill now. I was there on Sunday and had to unplug her computer to move in a new desk and hook it up, so I unplugged everything. I plugged everything back in and all was fine...but at the time we didn't check the speakers. Today was the first time she tried her speakers and now they wont work. She has even tried unplugging her external speakers but she can't get any sound from the regular computer speakers now, which she could before. She tells me that nothing is muted on the computer and everything looks fine.

Any thoughts? Could anything have gotten "disabled" just from me unplugging and moving everything?