"sfc /scannow" utility will ONLY run in the optical disk drive used to install the operating system. It fails to run in any other drive = registry key value parameter problem:


  • This is a new and very bizarre problem:

    The optical drive used to install/reinstall the Windows operating system is auto-assigned a drive letter, and then this drive letter is auto-entered into the registry through the string in "RegEdit" as follows:  "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Setup".
    When clicking on the "Setup" folder at the end of this registry string, the “Installation Sources”, “Service Pack Source Path”, and "Source Path" values within it all have whatever drive letter was auto-assigned to the optical disk drive used to install/reinstall the operating system - for example, "E:\", "F:\" – or whatever drive letter was auto-assigned.
    The effect of this limitation within the parameters of this registry "Setup" folder’s values is that utilities - especially like "sfc /scannow" - WILL NOT RUN IN ANY DRIVE THAT DOES NOT HAVE THE CORRESPONDING DRIVE LETTER ASSIGNED TO IT.
    So, for example, if you have multiple disk drives in your PC, an error dialogue box will open if you try to run "sfc /scannow" in any drive that is assigned any other letter than the one in these “Source” registry values.  The result is that the XP reinstallation CD-ROM is simply not recognized when inserted into a drive with another assigned letter.  Error dialogue boxes pop up and say that you have not inserted the XP reinstallation CD, and will repeatedly ask for it, saying you've put the wrong CD in.

    However, if you eject the XP reinstallation CD from the drive that is NOT assigned the same letter as is in the “Source” registry values mentioned above, and then insert the CD into the drive that DOES have the corresponding drive letter, the error boxes will disappear off your PC's screen, and "sfc /scannow" will run & complete successfully.
    THIS IS A VERY NEW ISSUE, and one I've never had to deal with until approximately 2 or 3 months ago.  Before then, "sfc /scannow" would run successfully in ANY drive I put the XP reinstallation CD-ROM in - NO MATTER WHAT DRIVE LETTER WAS ASSIGNED TO IT.  This leads me to wonder if this registry value was changed by one or more of the automatic updates released by Microsoft during the last few months.
    It must be pointed out that this problem has nothing to do with the operation of the disk drives themselves whatsoever.  Also, uninstalling/reinstalling the disk drives, deleting upper & lower filters from them within the registry, and making sure their firmware/drivers/software is up-to-date all do nothing to correct this problem.  Further, the disk drives successfully autoplay/install from the XP reinstallation CD-ROM, all other driver/software CD-ROM’s, and will play any and all DVDs and CDs inserted into them successfully.  Doing complete, “raw”, fresh reinstallations of the O.S., Microsoft’s automatic updates, and any other drivers/software to completely restore the PC does NOT correct this problem either.  I tried doing such a “raw” reinstall twice in the same day – the same problem still existed.  Finally, this issue has absolutely nothing to do with ANY 3rd-party software – it is due to the automatically-entered, Windows O.S. registry’s “Source” drive value, as explained above.  This is the ONLY problem issue in an otherwise perfectly-operating computer system.

    Unfortunately, the level of Microsoft technical support available from "”, and M.S.’s phone support, was unable to determine how to remove this self-limiting, “Source” drive-letter value from the registry, so the "sfc /scannow" utility would again be able to run in any optical disk drive, regardless of the letter assigned to it.
    I therefore ask that Microsoft’s software design developers and engineers research this issue, and respond with steps to reset the values in this registry key's "Setup" folder so that the auto-assigned “Source” drive letter is either removed, or the values within the “Setup” folder are modified so as to allow the "sfc /scannow" utility - and anything else impacted by this self-limiting drive-letter value - to run properly, regardless of the drive letter assigned to any disk drive any customer has that is other than the one auto-assigned as the O.S. installation “source” drive letter.
    The requested outcome of changing the registry in this manner is - considering all optical disk drives start with the letter "D" and go on from there, potentially being assigned letters up to and including "Z" - that ALL drives can be used to run "sfc /scannow" successfully, WITHOUT having to reassign any of them the same letter as the one in the “Source” registry values.
    I ask that Microsoft's software design developers and engineers provide me, and all Microsoft customers, with either automatic updates that correct this registry key's values to create the desired outcome mentioned above, or provide the detailed steps necessary to reset the registry’s values that cause this, and any similar, self-limiting problems so that "sfc /scannow" will run in ANY disk drive, regardless of its assigned letter.

    Further, that this self-limiting drive-letter value was put into the registry in the first place should be eradicated so that NO disk drive letter is saved/specified as a “source” drive, and therefore no disk drive letter is singled out as the only one that utilities such as "sfc /scannow" will be able to use to successfully recognize the XP reinstallation CD-ROM, and run the utility.
    Thank you, and I look forward to your prompt replies/solutions.

    Friday, September 11, 2009 2:57 AM

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  • This forum is for helping people on writing their unfinished software that is going to run on Windows. Visit a forum that covers Windows instead.

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    Visual C++ MVP
    Friday, September 11, 2009 5:45 PM