My zoiper, is on Windows XP and now there is no sound on a call
incoming or outgoing calls have no incoming or outgoing sound.
The audio wizard works great. Speakers OK Mic OK.
This guide might help, although it's for Zoiper5, the issue pretty much caused by the same: https://www.zoiper.com/en/support/home/article/14/Missing_or_one_way_audio
nice veey nice !