"Access Denied" on Hyper-V in workgroup setup after fresh Win 10 install

Question

I'm attempting to connect to a Win 2012 R2 Hyper-V server on a home network in a WORKGROUP setup using the Hyper-V Manager on my Windows 10 Pro laptop. All machines are local to the network. I had to do a reinstall of the OS on my Windows 10 Pro laptop and this is when the issue started.

Previously, I was able to connect just fine. I had:

• Added the host as a trusted host on my laptop using Set-Item WSMan:\localhost\Client\TrustedHosts -Value 'HOST1'
• I went into DCOMCNFG to allow remote access for anonymous login.
• Disabled all firewalls
• Set the local admin password for the host under Network Passwords on my laptop

Nothing changed on the server, and I have two other Windows 10 machines on the same network that are able to connect to the server just fine using Hyper-V Manager.

The only difference here is this is a fresh install of Windows 10, and I understand some things changed in the Fall Creators Update, but I don't know what. I'm following the same steps, but when I try to connect to the server using Hyper-V Manager I get: Access Denied. Unable to establish communication between 'HOST1' and 'LANNISTER'. HOST1 is the server, LANNISTER is my laptop.

What else would I need to configure?

Answer 1

I would recommend checking the IP address you used the first time. If this was static IP address try to assign the old IP address to the new install and see if this helps. The reason is because on the Hyper-V server's HOSTS file (C:\Windows\System32\Drivers\etc\HOSTS), the IP to hostname mapping from your Windows 10 PC is no longer valid. You need to have an entry in the HOSTS file because both the Hyper-V server and the Windows 10 PC are not part of a domain. Hope this helps

Answer 2

I figured it out. There were two machine keys that were different between the machines that were able to connect and those that were not. I'm not too familiar with these, but I came across them in another post. I'm not sure if both are needed or just MachineAccessRestriction, but I was able to export the keys from the working machines and import them into the ones that were showing "Access Denied". After this, I was able to connect using Hyper-V Manager as normal.

I'm assuming my other machines that were able to connect did not have these keys modified when upgrading, but a fresh install of 1709 wrote different values.

The keys in question:

Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Ole\MachineAccessRestriction
Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Ole\MachineLaunchRestriction

Here are the working values that I imported into my laptop (these came from a working Windows 10 Pro laptop). Save the key below to a .reg file and open the file to import and overwrite these keys.

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Ole]
"MachineAccessRestriction"=hex:01,00,04,80,cc,00,00,00,dc,00,00,00,00,00,00,00,\
  14,00,00,00,02,00,b8,00,06,00,00,00,00,00,14,00,07,00,00,00,01,01,00,00,00,\
  00,00,01,00,00,00,00,00,00,14,00,07,00,00,00,01,01,00,00,00,00,00,05,07,00,\
  00,00,00,00,18,00,07,00,00,00,01,02,00,00,00,00,00,05,20,00,00,00,32,02,00,\
  00,00,00,18,00,07,00,00,00,01,02,00,00,00,00,00,05,20,00,00,00,2f,02,00,00,\
  00,00,18,00,03,00,00,00,01,02,00,00,00,00,00,0f,02,00,00,00,01,00,00,00,00,\
  00,38,00,03,00,00,00,01,0a,00,00,00,00,00,0f,03,00,00,00,00,04,00,00,a1,27,\
  60,8f,9a,bb,18,34,63,b6,77,ff,9d,d5,b6,6c,e7,32,1a,68,08,52,43,92,86,a6,1f,\
  d8,98,17,1b,3b,00,00,00,00,00,00,00,00,01,02,00,00,00,00,00,05,20,00,00,00,\
  20,02,00,00,01,02,00,00,00,00,00,05,20,00,00,00,20,02,00,00
"MachineLaunchRestriction"=hex:01,00,04,80,d0,00,00,00,e0,00,00,00,00,00,00,00,\
  14,00,00,00,02,00,bc,00,06,00,00,00,00,00,14,00,1b,00,00,00,01,01,00,00,00,\
  00,00,01,00,00,00,00,00,00,18,00,1f,00,00,00,01,02,00,00,00,00,00,05,20,00,\
  00,00,20,02,00,00,00,00,18,00,1f,00,00,00,01,02,00,00,00,00,00,05,20,00,00,\
  00,32,02,00,00,00,00,18,00,1f,00,00,00,01,02,00,00,00,00,00,05,20,00,00,00,\
  2f,02,00,00,00,00,18,00,0b,00,00,00,01,02,00,00,00,00,00,0f,02,00,00,00,01,\
  00,00,00,00,00,38,00,0b,00,00,00,01,0a,00,00,00,00,00,0f,03,00,00,00,00,04,\
  00,00,a1,27,60,8f,9a,bb,18,34,63,b6,77,ff,9d,d5,b6,6c,e7,32,1a,68,08,52,43,\
  92,86,a6,1f,d8,98,17,1b,3b,00,00,00,00,00,00,00,00,01,02,00,00,00,00,00,05,\
  20,00,00,00,20,02,00,00,01,02,00,00,00,00,00,05,20,00,00,00,20,02,00,00