Tuesday, 9 June 2009

Hyper-V Error – Access Denied. Unable to establish communication between Hyper-V and Client

While setting up a Hyper-V server for Wayne and Justin to work with some VMs to troubleshoot the SBS 2003 to 2008 replication error, we ran into a roadblock with getting the Hyper-V Manager connected to the Hyper-V Server 2008 box:

image

Virtual Machines

Access denied. Unable to establish communication between ‘Hyper-V Server’ and ‘Hyper-V Manager’.

This is puzzling since the workstation has been connected to this particular Hyper-V server many times using other network profiles. The profile we created for the Microsoft folks was seemingly giving us the connection issue.

The fix took a bit of searching to find and needed to be accomplished on the Windows Vista system where the Hyper-V Manager was installed:

  1. Close the Hyper-V Manager
  2. Click Start and type: %windir% [Enter].
    • A Windows Explorer window will open to the Windows directory.
  3. Type: dcomcnfg in the Search Windows field at the top right hand of the Explorer window.
    • You will see the following in your search results:image
  4. Right click on dcomcnfg and Run As Administrator.
    • Authenticate with the local admin credentials if UAC prompts for credentials, or Continue if it does not.
  5. Open the Component Services node, then the Computers node, then right click on My Computer and click on Properties.
  6. Click on the COM Security tab.
    • You will see the following:image
  7. Click the Edit Limits button under Access Permissions.
  8. Enable Remote Access for Anonymous Logon
    • Before and after shot:image
  9. Click Apply and OK.
  10. Close the Component Services console and the Windows Explorer window.
  11. Start the Hyper-V Manager and continue through the UAC.

The virtual machines, if any, will show up in the Hyper-V Manager console after that.

Thanks to Augusto Alvarez for the clearest and exact explanation for the fix:

Philip Elder
MPECS Inc.
Microsoft Small Business Specialists
Co-Author: SBS 2008 Blueprint Book

*All Mac on SBS posts will not be written on a Mac until we replace our now missing iMac! (previous blog post)

Windows Live Writer

at

87 comments:

  1. Anonymous19 July, 2009 03:55

    This is a great guide. Thanks a million.

    By the way, it also works on Windows 7.

    ReplyDelete
  2. Anonymous30 July, 2009 17:59

    Thank you for this informative post. It solved my problem.

    ReplyDelete
  3. Anonymous14 September, 2009 17:00

    Thank you, it worked perfectly.

    ReplyDelete
  4. Bradley23 September, 2009 10:34

    Wow! Thank you so much. Worked amazingly! I wonder what kind of security effects this has, if any.

    ReplyDelete
  5. Philip Elder Cluster MVP23 September, 2009 12:25

    Bradley,

    I am not sure where the conflict arrises from.

    We do have things buttoned down quite tightly via Group Policy, so there may be something there.

    You are welcome to all!

    Philip

    ReplyDelete
  6. daviasch07 October, 2009 13:44

    This is great, you saved me a lot of time.

    ReplyDelete
  7. Anonymous30 October, 2009 09:42

    How did you figure THAT out? Well done, you saved me tons of time.

    Micheal

    ReplyDelete
  8. David12 November, 2009 07:35

    Thank you for this guide. Very helpful!!

    Regards
    /David

    ReplyDelete
  9. PMM21 January, 2010 18:10

    Wow!Right at it! For three days I was installing and testing hypervisors. Citrix's did not discover half of my hardware, Vmware's - the other half, then came management issues. I knew from the beginning that I shoud stick to Microsoft, but the lack of a nice management console tripped me. Read about Admin Tools. FRESH installed Win 7 RTM 32 bit. Got this "Access Denied" Error.Decided that, because I have Hyper-V Server 2008 R2, I should manage it through a 64 bit OS. Installed Win 7 64bit. Got the error again. Was just about to erase everything and go back to vmware, when I read your detailed, step-by-step description. Decided to give it a try just befire hiting Enter on "Format" - litterally! And ... guess what - IT WORKED! :-) Thank you for taking your time to post such nice things here! You saved 4-days of nerves being wasted in vain. (Sorry for the long post - got emotional)

    ReplyDelete
  10. Unknown07 April, 2010 12:30

    Yeah, didn't work too well for me. Still getting the same error.

    ReplyDelete
  11. IL06 June, 2010 00:08

    @Justin May be five-parts guide http://blogs.technet.com/b/jhoward/archive/2008/04/04/part-5-domain-client-to-workgroup-server-hyper-v-remote-management-you-do-not-have-the-requested-permission-to-complete-this-task-contact-the-administrator-of-the-authorization-policy-for-the-computer-computername.aspx by John Howard will do for you.

    ReplyDelete
  12. IL06 June, 2010 00:20

    Better links are for do-it-all utility http://blogs.technet.com/b/jhoward/archive/2008/11/14/configure-hyper-v-remote-management-in-seconds.aspx and the Hyper-V authorization model explained http://blogs.technet.com/b/jhoward/archive/2009/08/31/explaining-the-hyper-v-authorization-model-part-one.aspx

    ReplyDelete
  13. Anonymous21 September, 2010 14:15

    Excellent post. Resolved my issue. Thanks a lot.

    ReplyDelete
  14. Anonymous06 October, 2010 10:15

    thanks a lot, it worked!

    ReplyDelete
  15. Divyanand30 November, 2010 02:06

    Tried on Win 7 Ultimate & it works like charm.
    Thanks.

    ReplyDelete
  16. Divyanand30 November, 2010 02:07

    Tried on Win7 Ultimate. It worked well. Thanks.

    ReplyDelete
  17. Anonymous30 December, 2010 08:55

    Wow! Amazing!
    I've been using RDP to connect to our HYPERV host for the past two months, since I couldn't the HYPERV MGR to work on my PC to connect to the server.

    Followed the steps in this guide, and now I'm able to manage the HYPERV server from my PC.

    Thanks a million!

    ReplyDelete
  18. Rolf Sørensen16 February, 2011 12:59

    You are THE MAN!
    Nowhere else could I find af solution to this strange problem.
    Thank you!.

    ReplyDelete
  19. Anonymous24 February, 2011 17:25

    Dude... you rock...

    ReplyDelete
  20. Anonymous05 April, 2011 01:31

    Big 10X from Russia! It fix my truble!

    ReplyDelete
  21. Anonymous27 April, 2011 17:24

    Perfect!!! Thank You!

    ReplyDelete
  22. Juan10 June, 2011 07:46

    Working perfectly under Windows 7 x64, but not working under Server 2008.
    Same user, same domain, following the same steps. Not sure what else to try without joining the HV to the domain.

    ReplyDelete
  23. Anonymous16 June, 2011 08:04

    Thank U very much !!

    ReplyDelete
  24. Hilli04 August, 2011 06:07

    Perfect! That did it!
    Searched for days...

    ReplyDelete
  25. Behnoud05 August, 2011 01:05

    Thank You.

    ReplyDelete
  26. Behnood05 August, 2011 01:05

    Thank You.

    ReplyDelete
  27. Anonymous24 August, 2011 04:08

    Exactly the correct solution, perfectly documented. Thankyou very much.

    ReplyDelete
  28. Anonymous22 October, 2011 11:23

    Great. Thanks :)

    ReplyDelete
  29. Anonymous31 October, 2011 13:15

    Life Saver! Thanks!

    ReplyDelete
  30. Anonymous26 November, 2011 00:19

    Appreciated... thankyou!

    ReplyDelete
  31. Anonymous12 December, 2011 06:00

    Thanks :)
    Worked like a charm
    Windows 7 => Windows 2008 Core

    ReplyDelete
  32. Anonymous02 January, 2012 11:11

    thank you very much this was so annoying to get this sorted - great post thanks so much

    ReplyDelete
  33. Anonymous17 January, 2012 00:22

    Thank you, it worked on Windows 7 Ultimate SP1.

    ReplyDelete
  34. Balbo03 February, 2012 06:27

    Hi,

    I get this error message. Anonymous Logon has already local access and remote access allowed.
    I tried HVRemote.
    Problem is not solved.
    Please help.
    regards

    ReplyDelete
  35. Balbo03 February, 2012 06:27

    Hi,

    I get this error message. Anonymous Logon has already local access and remote access allowed.
    I tried HVRemote.
    Problem is not solved.
    Please help.
    regards

    ReplyDelete
  36. Anonymous10 February, 2012 01:38

    Hi,

    After I reinstalled my Windows 7 machine I was not able to connect anymore and received the error: ""Access denied. Unable to establish communication between..."

    After changing the DCOM setting I was able again to vonnect to my Hypervisor. I did this previously, nut I compltely forgot about it.

    So thank you very much for this great article.

    Cheers, Jan

    ReplyDelete
  37. Anonymous10 April, 2012 13:12

    This helped fix my issue! Thanks for sharing.

    ReplyDelete
  38. Anonymous06 May, 2012 12:44

    Wouldn't have been able to fix my problem without this guide. Was really stumped. One of the clearest, most helpful posts I've ever used. Thanks

    ReplyDelete
  39. Anonymous15 May, 2012 03:24

    Thank you!!!

    ReplyDelete
  40. Anonymous14 September, 2012 07:29

    Just when I was about the pull ouy my VMware 5.1 install disk, I found this blog entry. I am using the Hyper-V 2012, free edition and Windows 8 Hyper-V Manager and it solved my problem.

    Thank You, Thank You!!!

    ReplyDelete
  41. Anonymous21 September, 2012 15:23

    Thanks!! You Rock!! Love Google and people like you that post these fixs.

    ReplyDelete
  42. Anonymous29 October, 2012 15:39

    BTW also still an issue between Windows 8 and server 2012 thanks so much you have helped me not want to tear my hair out!

    ReplyDelete
  43. Anonymous27 November, 2012 16:32

    I officially love you! I have spent days trying to get round this problem!

    I kiss you on both cheeks! :O)

    ReplyDelete
  44. Absoblogginlutely!13 December, 2012 08:06

    Philip - yet again you're da man. We tried fiddling around with hvremote and couldn't get remote access to work, but this solved the problem. Thanks a bunch.

    ReplyDelete
  45. Anonymous08 January, 2013 08:36

    Problem solved, thanks.

    ReplyDelete
  46. Anonymous26 February, 2013 12:50

    bless you !

    ReplyDelete
  47. Anonymous27 March, 2013 04:02

    Great. Now you opened your computer so that you allow anonymous login to your PC. Both localy and by RAS. Great work.

    ReplyDelete
  48. Philip Elder Cluster MVP27 March, 2013 21:55

    To the above post: Proof of concept please?

    Let us know how exactly one could utilize this bit to make changes on a remote system.

    Philip

    ReplyDelete
  49. Anonymous27 April, 2013 15:22

    Great.. It works...

    ReplyDelete
  50. Anonymous11 May, 2013 09:57

    It is great. Thanks a lot.

    ReplyDelete
  51. Anonymous17 May, 2013 12:56

    Thank you.

    ReplyDelete
  52. Afro07 June, 2013 16:53

    Thank you.

    ReplyDelete
  53. Unknown11 September, 2013 11:41

    You rock. Thanks.

    ReplyDelete
  54. Unknown11 September, 2013 11:42

    You rock, thank you!

    ReplyDelete
  55. Christer14 September, 2013 10:42

    Works fine on a Windows 8,1 system.

    Everything been working fine but then I installed some updates yesterday (windows update) and Hyper-v gave me this error :-(

    ReplyDelete
  56. Anonymous30 October, 2013 03:58

    Thanks HEAPS!!!!
    I used this method on Windows 8 after installing RSAT and it resolved Hyper-V manager connecting to the Server 2012 R2 Hyper-V server.

    ReplyDelete
  57. Craig18 November, 2013 05:33

    Thanks for the tip. Applied in Windows 7 Enterprise with SP1 after adding Hyper-V tools feature.

    ReplyDelete
  58. Anonymous28 January, 2014 01:22

    Awesome! Thanks a bunch.

    ReplyDelete
  59. Anonymous29 January, 2014 21:15

    Had to do this too on Windows 8.1 Enterprise. Thanks!

    ReplyDelete
  60. Paul30 January, 2014 23:12

    I had to do this to get Hyper-V Manager working on Windows 7 Professional. Theres's no domain, just my personal HP server at home. Worked like a charm! Thanks so much man!!

    ReplyDelete
  61. Unknown13 February, 2014 14:10

    Thanks, it works in Windows 8 as well.

    ReplyDelete
  62. rabi11 March, 2014 13:46

    merci pour l astuce great thank

    rabi

    ReplyDelete
  63. Chris17 June, 2014 00:41

    I was stuck with this issue for hours and then found this blog. Thank you so much! Cheers!
    Chris

    ReplyDelete
  64. Anonymous10 July, 2014 19:25

    Thanks

    ReplyDelete
  65. Anonymous27 July, 2014 21:35

    I'm reviving an old post only to say, I found this link and got my Hyper-V to work between Windows 8.1 pro / Windows Server 2012 R2 Standard.

    Just want to say thanks a lot !

    Regards,

    ReplyDelete
  66. Anonymous14 September, 2014 20:15

    Still Works!! Used this to establish connection between Win 8.1 and Hyper-V server 2012r2

    ReplyDelete
  67. Anonymous30 November, 2014 12:33

    Works! Thank you!

    ReplyDelete
  68. Anonymous28 January, 2015 11:24

    Extraordinary !!!!
    Thanks

    ReplyDelete
  69. Anonymous04 April, 2015 06:10

    thx

    ReplyDelete
  70. Anonymous24 June, 2015 14:42

    Appreciate the help! The guide was perfectly on target!

    ReplyDelete
  71. armyeyes16 July, 2015 21:43

    Thx

    ReplyDelete
  72. Anonymous24 July, 2015 13:50

    Thanks!!! Worked.

    ReplyDelete
  73. Anonymous03 August, 2015 01:57

    In my case, my user had for some reason lost the read/write permissions to the following registry keys.
    1. HKLM\Software\Microsoft\WBEM\CIMOM
    2. HKLM\System\CurrentControlSet\Services\WinSock2\Parameters

    You can also launch “dcomcnfg” through “Run”. (WIN + R)

    ReplyDelete
  74. Unknown03 September, 2015 06:46

    Sweet! Thanks guys.

    Can confirm that this also works with Windows 8.1 and will also likely work with 10....

    ReplyDelete
  75. Anonymous29 September, 2015 16:10

    Thank you for the post!!

    ReplyDelete
  76. Traberg11 October, 2015 08:46

    Thanks - it also works with Win 10.

    ReplyDelete
  77. Praveen11 January, 2016 00:13

    Thanks.. This worked for me as well...

    ReplyDelete
  78. Anonymous17 February, 2016 09:25

    Thanks, works with win10 as well.

    ReplyDelete
  79. Anonymous31 March, 2016 05:18

    Thank you very much. I've been trying from a week to solve this problem.

    ReplyDelete
  80. Anonymous02 May, 2016 12:46

    great thanks worked great for me too.

    ReplyDelete
  81. Anonymous05 July, 2016 14:24

    Great work. Thank you. VC @ Cali

    ReplyDelete
  82. Kliment Andreev28 August, 2016 07:37

    Excellent!

    ReplyDelete
  83. Anonymous27 October, 2016 02:15

    Thank you, great tut. Is this caused by Windows Updates?

    ReplyDelete
  84. Dmytro O20 February, 2018 01:14

    It doesn't work on Windows 10 1709. Holy crap on M$!

    ReplyDelete
  85. nagytestvir19 November, 2018 09:08

    why doesn't work on Windows 10 1709 and 1803 ???

    ReplyDelete
  86. Philip Elder Cluster MVP19 November, 2018 11:08

    NOTE: This "fix" allows for anonymous access thus the block in later versions of Windows 10 I think.

    One way to do this is to run as a Standard User on the management machine so as to credential with UAC using admin credentials. That will allow for a secure way of accessing the remotely managed Hyper-V.

    Or, set up a Privileged Access Workstation which is an even better practice!

    ReplyDelete
  87. Unknown23 June, 2022 08:04

    Muchas gracias me sirvió muchísimo, Saludos desde México.

    ReplyDelete

NOTE: All comments are moderated.