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

87 comments:

Anonymous said...

This is a great guide. Thanks a million.

By the way, it also works on Windows 7.

Anonymous said...

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

Anonymous said...

Thank you, it worked perfectly.

Bradley said...

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

Philip Elder Cluster MVP said...

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

daviasch said...

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

Anonymous said...

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

Micheal

David said...

Thank you for this guide. Very helpful!!

Regards
/David

PMM said...

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)

Unknown said...

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

IL said...

@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.

IL said...

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

Anonymous said...

Excellent post. Resolved my issue. Thanks a lot.

Anonymous said...

thanks a lot, it worked!

Divyanand said...

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

Divyanand said...

Tried on Win7 Ultimate. It worked well. Thanks.

Anonymous said...

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!

Rolf Sørensen said...

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

Anonymous said...

Dude... you rock...

Anonymous said...

Big 10X from Russia! It fix my truble!

Anonymous said...

Perfect!!! Thank You!

Juan said...

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.

Anonymous said...

Thank U very much !!

Hilli said...

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

Behnoud said...

Thank You.

Behnood said...

Thank You.

Anonymous said...

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

Anonymous said...

Great. Thanks :)

Anonymous said...

Life Saver! Thanks!

Anonymous said...

Appreciated... thankyou!

Anonymous said...

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

Anonymous said...

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

Anonymous said...

Thank you, it worked on Windows 7 Ultimate SP1.

Balbo said...

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

Balbo said...

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

Anonymous said...

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

Anonymous said...

This helped fix my issue! Thanks for sharing.

Anonymous said...

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

Anonymous said...

Thank you!!!

Anonymous said...

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!!!

Anonymous said...

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

Anonymous said...

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!

Anonymous said...

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

I kiss you on both cheeks! :O)

Absoblogginlutely! said...

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.

Anonymous said...

Problem solved, thanks.

Anonymous said...

bless you !

Anonymous said...

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

Philip Elder Cluster MVP said...

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

Anonymous said...

Great.. It works...

Anonymous said...

It is great. Thanks a lot.

Anonymous said...

Thank you.

Afro said...

Thank you.

Unknown said...

You rock. Thanks.

Unknown said...

You rock, thank you!

Christer said...

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 :-(

Anonymous said...

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.

Craig said...

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

Anonymous said...

Awesome! Thanks a bunch.

Anonymous said...

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

Paul said...

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!!

Unknown said...

Thanks, it works in Windows 8 as well.

rabi said...

merci pour l astuce great thank

rabi

Chris said...

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

Anonymous said...

Thanks

Anonymous said...

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,

Anonymous said...

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

Anonymous said...

Works! Thank you!

Anonymous said...

Extraordinary !!!!
Thanks

Anonymous said...

thx

Anonymous said...

Appreciate the help! The guide was perfectly on target!

armyeyes said...

Thx

Anonymous said...

Thanks!!! Worked.

Anonymous said...

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)

Unknown said...

Sweet! Thanks guys.

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

Anonymous said...

Thank you for the post!!

Traberg said...

Thanks - it also works with Win 10.

Praveen said...

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

Anonymous said...

Thanks, works with win10 as well.

Anonymous said...

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

Anonymous said...

great thanks worked great for me too.

Anonymous said...

Great work. Thank you. VC @ Cali

Kliment Andreev said...

Excellent!

Anonymous said...

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

Dmytro O said...

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

nagytestvir said...

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

Philip Elder Cluster MVP said...

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!

Unknown said...

Muchas gracias me sirvió muchísimo, Saludos desde México.