Windows 10: I can't turn on my laptop, it says " Your session was logged off because DWM crashed....

I have tons of documents in the laptop, and I'm really panic now

:)

 

Redegit there is dwm many why

Hello, Gianakl28377

Welcome to Microsoft Community.

DWM stands for Desktop Window Manager, a service that is responsible for rendering visual effects on the desktop, such as transparency, glass window frames, 3-D animations, and more1. DWM uses the registry to store and access various settings and policies related to its functionality.

The reason why you see so many DWM in registry is because each time a new session is created, DWM adds a new subkey and value under the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\DWM registry key. This can happen when you log on, switch users, connect to a remote desktop, or run an application that creates a new session. The number of DWM in registry can also increase if some sessions are not properly terminated or cleaned up by the system.

You can use the following steps to check the number of active sessions on your system and compare it with the number of DWM in registry:

• Press Ctrl+Shift+Esc to open Task Manager.
  
• Click on the Users tab to see the list of users who are currently logged on or connected to your system.
  
• Click on the Details tab to see the list of processes that are running on your system.
  
• Sort the processes by the PID column to group them by their session identifiers (PID).
  
• Count the number of unique session identifiers that you see in the Details tab. This is the number of active sessions on your system.
  

If the number of active sessions matches the number of DWM in registry, then there is nothing to worry about. However, if the number of DWM in registry is much higher than the number of active sessions, then it might indicate that some sessions are not properly terminated or cleaned up by the system. This can cause performance issues or errors with DWM or other applications that use desktop composition.

When your screen turns yellow, it might be because you've activated night mode or other software's blue light filter. These modes adjust the screen's color temperature to make it warmer, reducing eye strain. However, they can affect the transparency effects of the Desktop Window Manager (DWM) because DWM calculates transparency based on the screen's colors.



When you turn off night mode or the blue light filter, the screen's color temperature returns to normal, but DWM's transparency effects are also turned off. This happens because DWM detects the change in screen colors and recalculates transparency. If you want to maintain DWM's transparency effects, you may need to turn off night mode or the blue light filter.

Additionally, you can ask questions in your most comfortable language; it doesn't have to be in English.

Please let us know if you have any other concerns.

Best regards

Yuhao Li

Microsoft Community Technical Support

 

Are UMFD and DWM Logon Sessions Destroyed on Restart, Even if Event Viewer Doesn't Say?

usually when I log off and shut down my PC, you can look back to that time in Event Viewer Security logs and see 3 specific IDs

4648, 4624, and 4634, which are all related to UMFD/font drive host and DWM/Windows Manager sessions that get created on every startup. when I shut down, they get logged off, which is what the 4634 events are for

however, I found that last night when I shut my PC down, there were no 4634 events, just the 4648 and 4624 events for UMFD and DWM. there weren't even any logoff events for my actual User account

the new logon IDs for the current UMFD and DWM sessions are different but I'm confused as to why there were no 4634 events, because it makes it sound like they were never logged off

I've checked all the startups that I can, as far down as the Security log goes (the 18th), and it's never missed a 4634 event between then and now

so my question is; even if Event Viewer doesn't show any 4634 events for those sessions, are the User, UMFD, and DWM sessions destroyed and replaced on every restart?

 

dwm failure on rdp session in win 10

When logged in to a Win 10 pro system remotely from a Win 7 pro system, two instances of the dwm process are created. Only one appears when logged into the same system locally.

One of the two processes in the rdp session seems to be dormant, accumulating no cpu usage. However, the second dwm process seems to have an event processing thread in the dwmcore DLL that is hung in a tight loop, thus consuming a core of a multicore processor.

dwm version is 10.0.10240.16384...interesting versioning!