Ubuntu – no audio on windows guest after installing vbox guest additions

System inbuilt components like LAN, Wifi, soundcard,or graphics card will be used from the host OS. They will be virtualized using an emulation for the guest OS. In many cases you are able to choose from different emulation modes in the virtual machine settings.

Therefore you can not install these drivers to your guest OS.

However some external components like USB attached devices (e.g. printer, scanner, Bluetooth dongle) do need an additional driver for the guest OS. In Windows you will be asked for these drivers as soon as you capture the device from the Virtual Box Manager.

Note: for full USB 2.0 support we need to run the PUEL version of Virtual Box that to date is on version 4.1.8.

Having experienced the same Windows guest stutter under an Ubuntu host (12.04) - except in Win 8.1 - I found a solution that mostly conforms with Takkat's answer. My stutter occurred with the Windows guest being allocated 4 out of 4 cores, but the execution capped at 75%, with 4GB RAM, and 256 MG graphics RAM. Switching to 2 out of 4 cores - but removing the execution cap - running at 100%, eliminated 90% of the stuttering. But not all of it.

The final 10% - and the total elimination of stuttering - came when I switched from the default PulseAudio driver in VirtualBox Manager's settings, to the ALSA Audio Driver. Please note, prior to the aforementioned reallocation of CPU's and execution caps, I had also tried this driver change, and it did not remotely eliminate the stutter. The two changes in combination was required.