First off before we go anything further the Desktop Windows Manager (DWM) is the windows manager that basically allows the use of hardware acceleration to help render the GUI of Windows. You will find this type of manager in Windows 7 & 8, Windows Vista, as well as several Window Server editions.
The DWM.exe file is a compositing window manager. What this means is that every program will have a buffer that will write data to. After that the DWM then will composite each buffer in the final image. Basically DWM.exe is a process within Windows itself and it is responsible for for managing all of the graphical and visual effects related processes going on with your desktop.
Why Is the Desktop Windows Manager Running
Your DWM is running because this process basically controls your themes, task-bar icons, window effects and everything else as mentioned that has to do with the Windows user interface. There is nothing wrong with the DWM.exe running. In fact is should be running.
While some people think you should remove or disable the process to help increase your laptops performance it is not something I am going to recommend. Instead of disabling the process why not do small things like using the Classic Theme on Windows or disabling your themes support.
Where is the DWM.exe File and Is it a Virus
The real DWM.exe is located in your C:\Windows\System32 however the drive may also vary depending on your system. Also notice I said the real DWM file. This is because sometimes you will find that there are viruses hidden on your laptop with the same DWM file name.
In some cases you may even find that the dwm.exe file itself is infected with a virus. If you have a laptop should always make sure you have some type of anti-virus software that you use to regularly check your system.
So in short no the DWM.exe is not a virus but there could be a virus on your computer that is named the same thing. This is not the real file but is using the name so that you will think its not the one causing the issues.
Using A Lot Of Memory
If you want to view the usage of the desktop windows manager all you need to do is open your Task Manager and go down to DWM.exe located under the Processes Tab. What people don’t seem to understand is that how much memory being use is totally up to you.
This process only uses memory when different Windows components are opened. So basically if you have a lot of components open you are going to see it use a lot more memory than expected. This is normal behavior for this process so the easiest way to save memory is to minimize the amount of programs/processes opened at once on your laptop.
Turning Off DWM.exe File
I don’t recommend you turning off the process. Even though a lot of people say hey it works and it’s better I don’t go into this simply because to me its not worth it and you probably should never do it. Hey though its your machine and you can do as you please.
There are a lot of articles that will tell you how to get rid of this process and stop it from running. Just Google Turn Of or Disable DWM.exe. This should have explained what the DWM.exe is, why it is running as well as why it uses so much memory. Think about of this and then you decide if this is something you want to get rid of.