Sound does not work in Windows virtual machine.
If I go to Device Manager (Start > in the search box type devmgmt.msc, hit Enter (return)) and expand Sound, video and game controllers I see Parallels Audio Controller without exclamation mark. This means that driver is properly installed:
If I go to Start > Control Panel > Hardware and Sound > Sound I see Parallels Audio Controller Speakers with green tick:
If I right-click Parallels Audio Controller Speakers and click Test the following error appears:
The current issue is not related to Parallels Desktop as Sound adapter works properly and necessary drivers are installed. Please contact Microsoft for the further assistance or repair Windows installation.