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Win8 slows down - explorer.exe scanning all the drive RRS feed

  • Question

  • I've got a strange performance issue with Win8 Enterprise. Quite often (al least once every day) it suddenly slows down - disk aktivity raises to max and I'm waiting minutes (!) for any response. By using Process Monitor, I found out that the most (and, in fact, the only) active process is explorer.exe, reading all of my data - folder by folder, file by file (all over the disk - in my user profile as well as outside it).

    Restarting explorer.exe stops explorer from scanning - for a few hours or a day.

    I don't think it might be some sort of malware as there is no network traffic when the scan runs, the "explorer.exe" file has valid signature, I didn't visit any "dangerous" website, I installed just a few proved apps and -last but not least- the Windows Defender scan found nothing...

    I tried to switch off Windows Defender, Windows Search and Superfetch services, but with no luck.

    Does anyone have a clue why such disk scan could occur and how to get rid of it?

    Friday, October 26, 2012 7:58 AM

All replies

  • Hi,

    Are you using Bitlocker?


    Blog: www.danielclasson.com/blog | LinkedIn: Daniel Classon | Twitter: @danielclasson

    Friday, October 26, 2012 1:26 PM
  • Make a xperf trace to see the cause. Install the WPT (http://social.technet.microsoft.com/wiki/contents/articles/4847.install-the-windows-performance-toolkit-wpt-en-us.aspx), open a CMD prompt with admin rights and run the commands from here:

    http://www.youtube.com/watch?v=0h-i_EfzadA

    Run it and after you captures the rise allocs and frees, go back to the CMD and press a key to stop capturing. Now compress the XperfSlowIOcir.etl as 7z (LZMA2, ULTRA) to reduce the size. Upload this file to your SkyDrive or Dropbox and post a link here.


    "A programmer is just a tool which converts caffeine into code"

    • Proposed as answer by Arthur Xie Monday, October 29, 2012 7:47 AM
    • Unproposed as answer by Arthur Xie Monday, October 29, 2012 7:47 AM
    Sunday, October 28, 2012 12:40 PM
    Answerer
  • What is the model of your computer? Try to upgrade the BIOS and hard drive firmware. If the issue persists, temporarily disable antivirus and see the result.

    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. ”

    Monday, October 29, 2012 7:50 AM
  • Hello, thank for all replies!

    I'm not using Bitlocker - but I'm using EFS folders (including my user profile). This worked fine in Win7 and Win8 also seems to handle it well.

    My computer is Asus K50IJ:
    http://www.asus.com/Notebooks/Versatile_Performance/K50IJ/
    I have already tried to disable antivirus (Windows Defender). I already have the latest BIOS/firmware - anyway, I see no way how BIOS/firmware might force OS to scan a partition...

    I will try the I/O perf diagnostics next time when the slow down appears and post back the results.

    Tuesday, October 30, 2012 9:04 AM
  • I will try the I/O perf diagnostics next time when the slow down appears and post back the results.


    have you used xperf?

    "A programmer is just a tool which converts caffeine into code"

    Wednesday, October 31, 2012 7:02 PM
    Answerer
  • The slow down has not appeared since my first post.

    I wonder whether it might have something to do with using Windows Explorer search tools. I noticed that Windows Explorer remembers my settings about searching file contents in non-indexed locations - and when the disk scans were occurring, I had that settings checked. Since I unchecked it, no file content scan has come back. 

    I wonder whether Windows Explorer might under some conditions restart or continue a search after closing the search window. This would exactly match the behavior I observed: explorer.exe reading file by file all of my disk...

    Thursday, November 1, 2012 11:15 AM