by XMog » Tue Jun 21, 2016 1:56 pm
That should be the only option that would cause beeping on each message when a window/channel is not in focus.
Two additional things to try:
In the Invision menu, open up the Sound Manager and disable sounds there. Invision's sounds are all artificial voice clips, not beeps, so that shouldn't be the problem unless you are missing sound drivers (unlikely), in which case mIRC may make the computer/mobo beep.
Or, go back into mIRC's options, "Sounds" section, and uncheck "Enable Sounds."