Windows 7 unknown devices

Hi,

I recently installed Parallels Desktop and configured the program in order to use my Windows 7 Boot Camp partition.
Unfortunately, some devices are not correctly installed, as you can see by looking at the attached image.
I guess one of the devices is the integrated audio chip, because I can't hear any sounds coming from the VM.
Any suggestions regarding the drivers' installation would be greatly appreciated.
Regards,

Giovanni M.