No Audio Device or Sound Icon

Hello,

I have a Dell 5510. I bought a pair of speakers at a yard sale. When I plugged them into my system they didn't work. I plugged my pair in and now they won't work. They worked before. I have tried everything I can think of. When I go into system and look under sound there is no audio device showing. The sound icon is gone from my tray. When I put in my Dell express installer Cd with the SoundMAX audio drivers I get this error: Device object not present. Restart the system & run setup again. This doesn't work. My audio driver is SIGMATEL Stac 92XX C-Major HD Audio. I trying to figure out if there is anything I can do. I'm thinking I'm going to have to go buy a or totally restore my system. I really don't want to do the last thing. Any help would be really really appreciated.