Audio issues with Windows 7/10 on the Acer Aspire One 532h-2ds and/or with Zoiper 3.5

Hello.

My name is Veronica,I'm working on a call center. At work we should use Zoiper 3.5 because this tool is free and it is able to integrate itself with the browsers and it allows to make calls to customers that we find through a management application which works through the browsers themselves. I'm using an old Acer Aspire One,where I have installed 3 different OSes : an old installation of Windows 7,Windows 10 and a fresh installation of Windows 7. For each OS I have a different but also similar problem I suppose,that does not allow me to work. When I use the old installation of 7,after having placed some calls with Zoiper,it freezes,prevents me to make further calls. I tried to remove some programs but the problem isn't gone away,so I have installed Windows 10 on another partition. This time the problem is that to make the customers hear my voice I should tick the option "hear the device",but many times,when I do this,Windows 10 hisses an annoying whistle and it crashes giving the error "Kernel data Inpage Error" and when it reboots it removes the check on that option and anyway,the few times that it does not crashes,customers can hear my voice very weakly. At this point I made a fresh installation of Windows 7. Here customers don't hear my voice even if I tick the option "hear the device" and sometimes,when I do this,it crashes. The odd thing is that on the first installation of Windows 7,customers can hear my voice without having to tick the option "hear the device",but as I said there I have the freezing calls problem. I have also made the backup of all the drivers installed on the old installation of Windows 7 and I restored them on the new one. Nothing. I passed also the audio and video tests that Zoiper asked me to do,for the mic and the speakers. At this poiint I don't understand what could be the next thing to try to resolve the issue. Please,someone wants to help me ? Thanks.