What Is Desktop Window Manager (dwm.exe) and Why Is It Running?

You are no doubt reading this article because you stumbled across the Desktop Window Manager process and are wondering just what it is. We’ve got the answer.

The Desktop Window Manager process (dwm.exe) composites the display of application windows before drawing it to your screen. This allows Windows to add effects like transparency and live taskbar thumbnails. This process is a vital part of Windows that you cannot prevent from running. 

This article is part of our ongoing series explaining various processes found in Task Manager, like ctfmon.exemDNSResponder.exe, conhost.exe, rundll32.exeAdobe_Updater.exe, and many others. Don’t know what those services are? Better start reading!

So What Is Desktop Window Manager?

Desktop Window Manager (dwm.exe) is a compositing window manager that renders all those pretty effects in Windows: transparent windows, live taskbar thumbnails, Flip3D, and even high resolution monitor support.

Instead of applications drawing their displays directly to your screen, applications write the picture of their window to a specific place in memory. Windows then creates one “composite” view of all the windows on the screen before sending it to your monitor. Because Windows is compositing and displaying the contents of each window, it can add effects like transparency and window animations when layering the windows for display.

Can I Turn Desktop Window Manager Off?

No, you can’t. Back in the Vista days, Desktop Window Manager was controlled through a service that you could turn off—and in turn disable all the visual effects. Starting with Windows 7, Desktop Window Manager became a more integral part of Windows, that’s vital to creating the graphical user interface. That integration has deepened even further in Windows 8 and 10.

The good news is that Desktop Window Manager has gotten a lot better about how it manages resources, and you shouldn’t really need to turn it off.

What Can I Do If It’s Using Up RAM and CPU?

Desktop Window Manager should use fairly minimal resources. On my system, for example, I’ve got half a dozen active apps running, including Chrome, which has got more than a dozen tabs open. Even then, Desktop Windows Manager is using a little less than 1% CPU and about 60 MB RAM. That’s a pretty typical load. You should rarely see it creep much higher than that, and even if it does spike higher on occasion, it should settle back down quickly.

If you do see Desktop Window Manager eating up more RAM or CPU than you think it should, there are a couple of things you can try:

  • Make sure you have your hardware drivers updated, especially the drivers for your video card or integrated graphics adapter. Desktop Window Manager offloads a lot of work to your GPU to reduce load on your CPU.
  • Check your computer for malware. Some types of malware are known to cause issues with Desktop Window Manager.

Those are both good places to start.

Could this Process Be a Virus?

The Desktop Window Manager process itself is an official Windows component. While it’s possible that a virus has replaced the real process with an executable of its own, it’s very unlikely. If you’d like to be sure, you can check out the underlying file location of the process. In Task Manager, right-click the Desktop Window Manager process and choose the “Open File Location” option.

If the file is stored in your Windows\System32 folder, then you can be fairly certain you are not dealing with a virus.

That said, if you still want a little more peace of mind, you can always scan for viruses using your preferred virus scanner. Better safe than sorry!

Walter Glenn is a long time computer geek and tech writer. Though he's mostly a Windows and gadget guy, he has a fondness for anything tech. You can follow him on Facebook and Twitter.