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Windows 7: dllhost.exe (COM Surrogate) consumes all CPU memory

19 Jan 2014   #1

Windows 7 Home Premium (64-bit) Service Pack 1
dllhost.exe (COM Surrogate) consumes all CPU memory

Let me mention at the outset that I am an intermediate Windows user.

I do not know the what-how-why of Windows registry values. Windows Task Manager is what I use to keep a watch on different processes running on the computer.

Lately, I have started encountering this problem of dllhost.exe (sometimes only one instance, other times multiple instances) gobbling up my computer's entire CPU memory resulting in a crash/error message. After reading many articles online on possible solutions, I've installed two Sysinternals utilities - Process Explorer & Process Monitor.

However, I am a newbie as far as these two softwares are concerned and it will take a while in understanding to use them to figure out what is causing the dllhost.exe CPU gobble-up problem. Besides, all the technical stuff - processes>threads>dlls, registry values etc. scares me.

I'd really appreciate if someone can help me figure out and fix the dllhost.exe problem.

1. dllhost.exe starts hogging CPU memory when I browse/watch/view jpegs, media files (.mp4 etc.). At times there is only one instance of dllhost.exe, other times there are multiple instances.

dllhost.exe (COM Surrogate) consumes all CPU memory-dllhost.exe-com-surrogate-problem-1.jpg

dllhost.exe (COM Surrogate) consumes all CPU memory-dllhost.exe-com-surrogate-problem-2.jpg

1. Problem seems to arise when I browse/watch/view jpegs, media files (.mp4 etc.)
2. It seems the problem might have a connection with 3D video files

What I have tried/done till now to resolve the problem
1. Run sfc /scannow command (System File Checker) in the command prompt several times. It says everything is in order.
2. Have up-to-date virus, malaware definitions of Microsoft Security Essentials & Malwarebytes Anti-Malware. Run full system scan with both multiple times, they did not find anything suspicious, scans come clean.

Please tell me what to do to fix the problem. I can share log files of different softwares, utility tools if that will help diagnose the problem. I hope this is not a virus/malaware/trojan disguised as a legitimate process. It has been an unnerving 2-3 days since the problem cropped up. Help!

My System SpecsSystem Spec
19 Jan 2014   #2

Windows 7 32 bit

If you notice the problem, look in task manager for mobsync.exe. I had issues with it. But it was more troublesome in Vista than Windows Seven. It seems to exist in order to make every media file on the system available to WMP. Sort of like a file indexer for media files.

Another possibility is if you have your Lan set to share media files over the network with WMP. Same type of thing. It searches every drive on your system looking for media files.

Please post back if you see evidence of either of the above.

If nothing shows up regarding mobsync then as a last resort see this:
COM Surrogate Error - Microsoft Community

btw on Vista I fixed the disk hogging CPU eating problem by using a program that killed mobsync.exe every time it tried to start.
My System SpecsSystem Spec
04 Feb 2014   #3

Win 7 Ultimate x64

Hi, h2Kj9zY5!

Give a look at this:
High CPU Usage by COM Surrogate - Microsoft Community

My System SpecsSystem Spec

09 Feb 2014   #4

Windows 7 Home Premium 64bit

I have the same problems when viewing videos.
The ones with wmv format not showing thumbnail and then messagebox appeared saying com surrogate stopped working and dllhost gobbling up the memory to 80%.
My System SpecsSystem Spec
27 Feb 2014   #5

win7 64
partial fix

Partial Fix:

Turn off thumbnail preview. On folders with video (especially 3D), only use small icon, list, or detail views.

Problem is caused by a problem with the thumbnail logarithm.
My System SpecsSystem Spec
04 Mar 2014   #6
Brian Gaeddert

Corrupt wmv on desktop

Had a corrupt wmv file on my desktop. This site helped me fix it. Good Luck.

dllhost.exe High Processor Usage Fix
My System SpecsSystem Spec
09 Apr 2014   #7

Windows 7 pro 64 bit
dllhost.exe COM surrogate fix

As mentioned by MilesAhead and Sir JB7 earlier, it's the update KB2670838 which causes this problem. See this long thread about this issue Why does dllhost.exe Com surrogate consumes memory until crash - Microsoft Community My PC would stall and crash when browsing folders with large amounts of thumbnails. I uninstalled the update. Please note that IE 9 and IE 10 are uninstalled also as a result but I don't use IE so its not an issue with me. PC is fine now and my 8G ram is being used correctly. Apparently this issue has been known since Vista and is worse if you have 3d videos in a folder for some reason. Regards, Brian
My System SpecsSystem Spec
10 Apr 2014   #8

Windows 7 pro 64 bit

For those of you who have to use IE10 and IE11 there is another way of dealing with this memory issue. I reinstalled both of them through windows update and low and behold the dcom fix KB2670838, despite me not choosing to download it, (it was marked as optional) has reappeared on the system. The whole memory hogging problem began again when I accessed the folder with the 3D movie. This time I deleted the movie, as I have a backup of it on an external drive and the memory problem has gone away. I did have to kill the dllhost.exe process in the task manager first though as the file would not delete. A soon as the process halted the offending file was deleted. Bit of bummer for anyone wanting to work with 3D movies and videos though. However it does not appear to happen on every system so there is probably something else involved, certain codecs perhaps or media players perhaps? Regards
My System SpecsSystem Spec

 dllhost.exe (COM Surrogate) consumes all CPU memory

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