Issue with mounting new ISO files from TechNet in Windows 8 and Windows 8.1 Preview

posted in: Blog | 72

Microsoft Windows 8.1 logo
Yesterday, I downloaded Windows 8.1 Enterprise Preview, so I could install it on my Surface Pro. I went to TechNet, downloaded the ISO, everything seemed fine, but then I tried to mount the ISO.

Mount ISO Windows 8 8.1

This is the error that I received:

“Sorry, there was a problem mounting the file.”

Mount ISO error Windows 8 8.1

I thought that it might have been my download that was corrupt, so I downloaded it once again, tried to mount it, but still with the same error. My conclusion was that there was something wrong with the ISO from TechNet or that there was some bug in mounting the file in Windows 8.1 Preview.

Today, I downloaded the Windows Server 2012 R2 ISO from TechNet, and tried to mount it on another computer with Windows 8. Same problem as yesterday!

After some Googling around, I found a couple of other people having the same issue. Apparently, there’s a flag that is set on the ISO file, which makes it unmountable.

The solution:

  • Make a copy of the ISO file, place it anywhere and then mount it

I’m not sure why this happens, but if you have any more information about this issue, please leave a comment!

72 Responses

  1. Mansoor Nathani

    I had the same issue. Definitely some issue with Windows 8.1


  2. SHK

    Man you just need to “unblock” Internet-downloaded files.
    Press Alt+Enter on file in Explorer. Push unblock button, viola!A file are ready for anything…

  3. Michael Batman

    Thanks Daniel, did the same thing (2 downloads with same result) and got quite frustrated. Copied and pasted then ran the file again and worked first time. Thanks once again MS

  4. john werneken

    What I see is this: Mount *.iso, error is thrown; check drive list, it was mounted after all as new drive.

  5. Michael

    Thanks Daniel, Copied and pasted file to my desktop and it worked the first time I tried it. Great simple workaround to a major problem. Thanks again.

  6. Kathy

    Yayyy!!! Thank you, thank you sir, it worked! 😀 God bless and more power!

  7. Jefferson

    I still have the trouble even aftr changing the file location. Someone help me out!

  8. Kamran Shahid

    Thanks a save me re-downloading a 2.8 GB VS2013 ultimate edition

  9. Lynn

    I downloaded Microsoft office –and can’t install.. it’s telling me there is a problem mounting the file. Have no clue what an ISO is and how to fix this

  10. Solomon

    Awesome Daniel.

    Brilliant – Your solution worked. Here i am ready to enjoy office 2013 – thanks to you!

  11. Morten Snedker

    I can’t get it to work. Tried several iso’s, without any luck. Tried copying as well. Still no luck. A couple of these iso’s I have used before without any problems, but after update to 8.1 it fails.


  12. PO

    I continued to get the error message after copying/pasting somewhere else. However, after I tried that three or four times I noticed that each instance was mounted already. So, even though I got the error code the .ISO had actually been mounted all along.

  13. Esther Conort

    Bravo Daniel, bravo! I cannot BELIEVE this was such a simple fix or that it REQUIRES a fix after all this time (…MS, get on this!). I need to prep this latest edition of Project before teaching my 7am class tomorrow. You have my sincerest gratitude! ELC ^_^

  14. Phil

    Microsoft site was no help. Was just about to try something drastic when I came upon your solution. Brilliant! Worked immediately and saved a lot of frustration and so easy too. Thanks a lot!!

  15. Chris

    I am using windows 8 for some reason my sql server will not work know more. When I try and access Sql management studio . I get “Cannot find one or more component . Please reinstall”. I go to the folder I see everything in need but it still will not work.I have reinstalled the application , I have all the client tools.

  16. Michael Washington

    Had the same problem, copy paste did not work either. Then discovered after looking at the drives on the computer that the reason it was not working was that when I downloaded the .iso with Windows 8.1 it automatically mounted the drive. The error is because the .iso is already mounted.

  17. MikeyO

    I had a similar thing trying to load a downloaded MS Office Pro 2013 onto my Surface 2 Pro last night.

    Solution, I removed the microSD memory card that was inserted and then the issue went away.

    I downloaded the ISO file on a different PC and copied it to my Surface Desktop via a memory stick so it was nothing to do with the internet-downloaded file being blocked.

    When I found the solution, I had deleted the file from my Desktop. Havng removed the microSD card, when I then inserted the memory stick containing the ISO file, it mounted without me having to do anything and showed itself as as CD drive. I ran the Install file for Office 2013 directly from this “CD” drive.

  18. Subhadip Khan

    thank you very much..!
    you are the man…. thakns a lot..!

  19. SmoledMan

    I have the same problem. Downloaded Office 2013 Professional Plus ISO and it won’t mount.

  20. BnSaLeH

    thank you sir. it is mounted after a small (copy paste) 🙂

  21. Alex

    I’ve looked all over online for a solution. I even with through scary registry alterations. This worked though! Thanks so much!

  22. sam

    Copied and pasted to my desktop. First time it didn’t work and still said problem mounting file. Second time it worked, opened up and I was able to run setup. Don’t know why but thanks!

  23. Lisa

    Yeah even with the error code, mine had actually mounted in Computer. Sigh…

  24. Ajit

    Thank You. After chasing the problem all over Microsoft in vain, I finally got a solution here that WORKED!!!

    Amazing that MS itself didn’t provide any clues about the problem or issues with downloading their trial software. Took me several days chasing MS for such a simple solution!!

    Thanks Again!!

  25. vinay reddy

    yippie it works ,
    thank u 🙂
    how do u find out solutions??

  26. Hanna

    Omg I was searching all day for a solution, and this helped me so much!
    Thanks for the help you are awesome!! <3

  27. P Vineeth

    Thanx man! Working by copying to another location on the same drive ! 🙂

  28. Todd

    I discovered that even thou it was throwing the error if I opened up my computer the .iso was still mounted. I didn’t have to make a copy of the .iso for this to work but I tested that method also. I still got the error but again the .iso was mounted in my computer anyway.

  29. Ilyas

    Wish I saw this yesterday – I downloaded the program again thinking my original one was corrupted and spent hours trying different tricks to install it!!! Thanks!

  30. Yen

    I went around different sites just to find answers on how to mount the iso file in Win 8. Probably tried 4 options but none worked. Finally I tried this and it worked. I can now enjoy Office 2013. Thank you!!!

  31. Mauro Chacón

    Awesome. Copying does the trick!!! It also happens in Windows Server 2012 R2.

  32. dipesh shah

    thank you very much Daniel… I just copy paste it and it worked for me.. much appreciated !!!

  33. Mark

    I had similar problem – got error message but didn’t realise that image was actually mounting. Once I realised it was mounting despite the error I found this post and saw the comment about micro sd card. I had one mounted at the time, although the iso I was trying to use was on the hdd. I ejected the micro sd and voila! No error message.


  34. Gustav Brock

    Same issue with Windows 10 Technical Preview.

    I had looked for the Unblock button, but it is not there.
    Copying (from Desktop to Desktop) solved the issue.
    Now the size of the file matches the used spaced. Used spaced is larger on the original download.

  35. Chris O'Shea

    Same here – got the issue with the Win 10 preview. Copying and pasting it worked for me too.

    I notice that the original file has the attributes ‘AP’, whereas the copied one just has ‘A’. Wonder if this P (sparse?) is the flag causing the issue? Had a quick look at removing it using attrib, but (on my Win 8.1 box at least) it didn’t seem to want to play.

  36. Sumaire

    Had this problem with W10 on my Surface Pro 3. When I looked, it was “mounted” in nonexistent drives. 😛

    Copied and pasted the file and then removed the microSD card as well.

    Working perfectly now. Thanks!

  37. Nathan Maluk

    Hi everyone. Had this problem. An ISO just needs to be Unsparsed, then you can mount the ISO. I have one iso, it’s weight is 225 GB so I won’t to copy it in another location just to be able to mount it 😀
    A fix is very simple for any ISO, just add this reg file and right click your ISO, select Remove Sparse and just mount it! 😀 Voila! Now you haven’t to copy your ISO, just use this simple fix.

  38. Deb

    I am trying to mount an ISO file of MS Visual Studio 2013. I have tried what you suggested above and it is not working. I have a Surface Pro 3 running Windows 8.1

  39. WuzzoUK

    As others have said, double clicking the iso does actually mount it. In my case, on a drive marked CD (on a Surface??). Then just run the setup.exe. Not sure removing the SD card makes a difference although that used to fix things when V8 preview was released, so things haven’t moved on much..

  40. Greg

    OMG! It actually worked! Unsparsing?! Nathan Maluk, Thanks!!

  41. Ronnie

    Took me some figuring out why this solution at first didn’t work for me. For some reason all the iso’s where read-only. After I remove the RO attribute the remove sparse works perfectly.
    Now I’m wondering, does anyone know how to use the remove sparse reg key as such that it first automatically removes the R using: ATTRIB -R “%1” before the fsutil command, All-in-1 nice remove sparse button?

    Tx in advance, Ronnie

  42. Peter

    Hi folks, unfortunately, it does not work for me – copying ISO to another location MUST BE copy not MOVE, works but that unsparsing thing does not. any hints on that?

  43. John

    I think I have a possible reason. I took your article and considered what “flag” might affect this. I just imagined that an ISO should always be read-only to make sense. Maybe it’s looking for that. I set the “read-only” flag in the properties for the files in question, and …

    Bam!! It mounts with no errors. Thanks to you I can now end this headache.

  44. Colonist

    Thanks ! It’s works ! funny joke windows 😀

  45. kalashnikov

    nah, none of the above worked. still getting the unable to mount image message.

    thanks microsoft, keeping our lives hard as usual….

  46. invegat

    I never got en_visual_studio_enterprise_2015_rc_x86_dvd_6649702.iso 3,994,929,152 bytes to Mount on Windows 7 or from the VirtualBox shared folder of Windows 10 Enterprise Insider Preview, but copying the file to a local directory in Windows 10 worked. I knew the ISO file was good because the SHA1 Hash generated by Get-FileHash matched.

  47. Rick

    Can somebody please explaine how set up the regedit fix. I have never worked with Regedit before. I’m doing something wrong but I don’t know what. When I right click the popup menu shows Remove Sparse. But when I click it I get a question which program to choose to open it. When I select Windows Explorer I get the mounting error message.

    Thanks in advance.

  48. Charlie Clay Jr

    Are you flipping kidding me?

    After 90 mins of jacking around with this. Copying and mounting really worked? Sheesh!!!

    Thanks anyway.

  49. sarmad

    hey guys, i found something rather interesting as I myself was experiencing this problem. right click on the ISO file, go to properties. just beneath the “read only” option, check for something which says ” this file has come from another computer, to protect….”; there is also an “unblock option in front of the note. uncheck read only, and click on unblock. apply, and see what happens. worked for me. hope the same for you guys

  50. arron

    If you mount the file from your desktop there is no need to mount from image file

  51. Marco

    his sparse attrib problem happens all the time with downloaded ISOs for me.

    Put this in a batch file and drag-and-drop the target file onto it (with Windows Explorer). Et voilà.

    fsutil sparse queryflag %1
    fsutil sparse setflag %1 0
    fsutil sparse queryflag %1

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