DWM.exe helps with rendering visual effects on the desktop as well as with various features such as glass window frames, 3-D window transition animations, high-resolution support and so on. Desktop Window Manager helps write each picture on the Windows to a place in the memory and creates a combined view of all of them on the screen and sends it to the display. This way, the operating system can use Hardware Acceleration to create smooth animations. It could also be used for creating transparent effects.