I have Windows 8.1u1 and sometimes after startup DWM isn't running which makes all Metro stuff black. The charms bar turns into permanent black bar and start screen is broken.

And when it runs I can see two instances of it with description DWM-2 and DWM-3

I can't find any correspoding service if there is any.

Anyone has any idea? 

I don't have Aero Glass btw.

 

What I did so far

• sfc /scannow - Found some corrupted files and repaired them, but I have no idea what files cause the log is too long and I have no idea what to search for

Edited November 28, 201411 yr by Blackbird256

Did sfc fix it? The log is divided into Info, Warning, Error, etc. Search for Error and that will point you to where it replaced stuff.

Not sure since I didn't want to reboot over and over. I'll report that tommorow.

Looking through the log sure is a pain.

Edited November 28, 201411 yr by Blackbird256

Sorry for doublepost, but so far it seems StartIsBack+ is the culprit. I'll leave it removed for now and we'll see.

report this to Tihiy in his topic: http://www.msfn.org/board/topic/163489-startisback-17/

It happened again and SiB is already uninstalled so false alarm I guess. Really p***es me off.

UxStyle isn't the cause either.

Scratch that. UxStyle looks like the most likely candidate so far.

Nope it's really random. I installed UXStyle and the theme I'm using. Restarted 2 times and turned off/on for cold boot and the bug is nowhere to be seen.

I really don't know what to do.

Edited November 30, 201411 yr by Blackbird256

Look what theme is specified in registry key HKEY_USERS\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\ThemeManager

DWM loads this theme at first and loading fails, whole DWM crashes.

The path seems to be correct, but I noticed something else.
All of the files have the "This file is from another computer and could be blocked due to security measures" like most of downloaded stuff has. I'll try to unblock them. Maybe it is some access issue like you say.
BTW it's xXiNightXx's Windows 7 Aero theme. I used this dude's old version for W8 and it was working perfectly. No issues.
http://xxinightxx.deviantart.com/art/Windows-Aero-478224917

 

regedit image just in case I missed something

http://i.imgur.com/BteyojY.png

 

Oh and I forgot to mention there is no error message whatsoever. It just isn't running in process tab.

Edited November 30, 201411 yr by Blackbird256

I don't say it is cause of the problem, but I guess that the AeroRoundClear.msstyles is unsigned theme. Look happens on startup:

1) UxTheme service tries to load this theme, but it fails because its signature does not match.

2) DWM starts up and asks UxTheme for current theme.

3) DWM gets invalid data (NULL or something), because there is no theme in UxTheme.

4) DWM crashes -> if you are lucky, it does not start again; if you are unlucky, it gets restarted and goes back to 2)

It's possible, but is there any to track this? I guess this kind of thing won't be in Event log.

I am using the same version of UxStyle I had on W8 as it's the newest for now.

Edited November 30, 201411 yr by Blackbird256

So the most likely culprit is definitely UxStyle. I am using bigmuscle's UxTheme Bypass and whole week I haven't encountered the bug yet. Will keep on reporting any changes to keep everyone informed.

Edited December 18, 201411 yr by Blackbird256

thanks for sharing the result of your investigation. Which theme do you use? Maybe it has something to do with the theme + UxStyle.

thanks for sharing the result of your investigation. Which theme do you use? Maybe it has something to do with the theme + UxStyle.

Already posted the link few posts above.

Also the same bug happens even with 8.1u2 so the update had no effect.

 

I'm going to guess it's the bug BM mentioned in this thread. His UxTheme Bypass uses the old DLL method which most likely starts sooner as it is executed on Windows startup compared to UxStyle which is running as a service thus the slight delay might screw with with DWM retrieving the theme and realizing it's unsigned. This definitely isn't the case on W8, but MS could have changed this behavior in 8.1.

Wish I could contact the developer of the UxStyle as I really like how it's easy to install.

Edited December 18, 201411 yr by Blackbird256

here is an email posted where you can reach the author:
 
http://withinwindows.com/
 
or contact him via twitter:
 
https://twitter.com/WithinRafael