If you’re stuck with Dragon Error 166 and cannot proceed further, then you must follow the instructions given below. This error occurs when profile. One of the most common causes of Dragon Error 166 is use of incompatible or outdated audio input devices. For speech recognition to be done accurately, dragon requires that high quality microphone be used. Therefore, if a microphone is outdated or incompatibility issues arise from using it with this software, then such user will get Dragon Error 166. For more details visit us www.dragonservicesupport.us