First off ,check that the speakers are not simply disabled on the bottom right hand corner of your toolbar,also right click on the speaker icon if there is one and check the correct tick boxes are ticked or not.
Next ,(Im assuming the speakers are external to your PC)since the speakers worked before installing the mike,try restoring computer back before you installed this software,go to Start,All programs,Accessories,System tools,system restore and follow its instructions
Charlie
December 2007