mmtask.tsk (not to be confused with mmtask.exe), which stands for Multimedia Task Support, is a Windows NT/2000/XP generic process for multi-tasking with multimedia applications so that several multimedia-related tasks can be open at once.
The process mmtask is not in any way a virus, a worm, a Trojan horse, spyware, or adware.
It is a system process which can be terminated.
