Please share the operating system and the error message you are getting while installing the drivers. You may check if the internal microphone is getting detected or not. Please follow the steps below:

I bought my Inspiron 14z from the official Dell store (India) in July 2012. There were some problems with it recently and I had a technician come and fix it (I think he either replaced the RAM or the motherboard.)

Each works fine on its own however - when we connect the monitor to the dock - we never can get it to get the native solution. We tried with HDMI, DVI, HDMI to DVI, DVI to HDMI.