nvmixertray.exe is a traybar process associated with a software package from NVIDIA. It gives you instant access to NVIDIA's ForceWare audio mixer settings.
Non-system processes like nvmixertray.exe originate from software you installed on your system. Since most applications store data in your system's registry, it is likely that your registry has suffered fragmentation and accumulated invalid entries which can affect your PC's performance. It is recommended that you check your registry to identify slowdown issues