this is most likely some kind of compatibility issue. Speakers are actually not needed for the exam, so you may ignore it in case you are 100% sure the mic works. There is a red bars indicator in the sound section to verify the mic is operational. Also, you may connect an external USB headphones or speakers just to check the mic during the compatibility test.
Please re-check your Sound settings. Check the output device. It is unlikely the newer system is not copatible with the sound card while the older one was. Not working speakers are, however, not a problem as speakers are not needed for the exam. The microphone is.