Unable to delete files from external HDD

By SimonDG · 5 replies
Mar 8, 2016
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  1. Hi guys. Just had this experience and am going to share my problem solving knowledge with you. I am running Windows10 on an older Toshiba Satelite Pro (which was becoming quite troublesome by the way with the Windows7.OS) but after installing the new Windows10 has actually been performing rather well again.

    Anyhow... I had a movie file on my external Seagate 2tb HDD that would not move/delete or respond to any inputs to move/delete or even shred with "file shredding" programs in an attempt to remove it completely. Even though the shredding programs would start the execution it was clear that NOTHING was actually happening! So with a little research, trial/error and consequently solving the problem, here is my advice..

    What you need to do when you are having this problem is open your "task manager" program and look down the list under "background running processes" for a program called "COMSurrogate". It will be using a rather large amount of memory to run. Right click and "End Task" on this program and it should close and disappear from the list. Go back to the offending file within your HDD directory and try to delete the file again.

    This was my experience and it worked for me fine. After having repeated trouble deleting this stubborn file from my HDD it finally removed itself, no questions asked. I had also had this problem previously but thought it unrelated, but when your computer is "glitchy" or "unresponsive" to commands to transfer/delete/move files either on your computer or through a HDD, check your task manager and end this program. I have no idea what it's for but this "COMSurrogate" program for whatever reason seems to cause a few problems with the OS and solves it when it is closed? Go figure...

    Hope this helps someone else now.
  2. Technician

    Technician TS Addict Posts: 677   +114

    The dllhost.exe process goes by the name COM Surrogate and the only time you’re likely even to notice its existence is when it crashes and you get the message COM Surrogate has stopped working. What is this COM Surrogate and why does it keep crashing?

    The COM Surrogate is a fancy name for Sacrificial process for a COM object that is run outside of the process that requested it. Explorer uses the COM Surrogate when extracting thumbnails, for example. If you go to a folder with thumbnails enabled, Explorer will fire off a COM Surrogate and use it to compute the thumbnails for the documents in the folder. It does this because Explorer has learned not to trust thumbnail extractors; they have a poor track record for stability. Explorer has decided to absorb the performance penalty in exchange for the improved reliability resulting in moving these dodgy bits of code out of the main Explorer process. When the thumbnail extractor crashes, the crash destroys the COM Surrogate process instead of Explorer.

    In other words, the COM Surrogate is the I don’t feel good about this code, so I’m going to ask COM to host it in another process. That way, if it crashes, it’s the COM Surrogate sacrificial process that crashes instead of me process. And when it crashes, it just means that Explorer’s worst fears were realized.

    In practice, if you get these types of crashes when browsing folders containing video or media files, the problem is most likely a flaky codec.

    Now that you know what the COM Surrogate does, you can answer this question from a customer:

    I’m trying to delete a file, but I’m told that “The action can’t be completed because the file is open in COM Surrogate.” What is going on?
  3. jobeard

    jobeard TS Ambassador Posts: 11,173   +989

    Even more basic, ANY TIME a file is opened in another process, that file can not be moved, renamed or deleted.
    The same is true for a directory, as when you (or a program) is positioned over a directory.

    Internally, the system is reference counting the number of active handles on the object and will not modify the object unless
    the reference count is ZERO.

    When the user attempts to alter the file or folder with a non-zero refCount, you should always see a system pop-up
    The action can’t be completed because the file is open ..."

    The solution is to Close all programs and retry. If it reoccurs, logoff and relogon (as it should be related to only your profile).
  4. Technician

    Technician TS Addict Posts: 677   +114

    I thought I made that clear, if not, thanks.
  5. jobeard

    jobeard TS Ambassador Posts: 11,173   +989

    The focus was on Com Surrogate and easily taken as the sole/root cause. I wanted to show there's far more possibilities:)
    best wishes.
    B00kWyrm likes this.
  6. Technician

    Technician TS Addict Posts: 677   +114

    True I did focus on his problem in particular, but in computing, many things carry over into other similar situations, and to know the cause of one such circumstance more fully can help to solve other problems that might be caused by the same (or similar) circumstances.
    Of course mentioning other instances directly helps drive that point home. :) Well done.

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