System Center Virtual Machine Manager (VMM) is generally reliable but does occasionally lose its ability to manage Hyper-V hosts. You may, for example, see a message indicating that the host needs attention or the host isn’t responding.
In this article, I’ll show you how to regain the ability to manage your Hyper-V hosts when these types of problems occur in VMM. Specifically, you’ll benefit from 3 basic checks and 4 slightly more advanced options to get your machine back on track.
Before we get into troubleshooting, let’s first understand what the Host Needs Attention error is.
What Is the Host Needs Attention Error?
A host needs attention error is a status indicator that appears next to a host within the VMM management console. You won’t typically see a pop-up error message or anything like that. The error indicates that VMM is unable to communicate with the host and essentially assumes the host is offline. That said, this error can occur even when a host is functional.
Why does your host need attention? It must be robust enough to survive. Well, let’s find out!
Why Does Your Host Need Attention?
Most of the time, a Host Needs Attention error doesn’t occur due to human intervention or error. It just happens. If, for example, a DHCP server assigns a host a new IP address and the DNS record doesn’t reflect the new address, this may result in an error. Of course, the error can also occur if the host is offline.
Before you delve too deeply into the troubleshooting process, check these 3 simple causes to see if they’re the culprit.
Check the Simple Things First
Sometimes problem-solvers delve into granular detail before checking the basics. Here are 3 things to check first before you look at more challenging issues.
1. Is the Clock Set Correctly?
Verify the clocks are correct on your domain controllers, Hyper-V hosts, and VMM server. Clock skew issues can cause Kerberos to stop working, which can lead to multiple other issues.
2. Is the DNS Name Resolution Working Correctly?
The server running VMM needs to be able to resolve the host’s fully qualified domain name to the correct IP address. It’s also worth taking the time to ensure the host’s IP address hasn’t changed and still matches the DNS record. I’ve experienced this issue numerous times.
3. Is the Host Functional?
Verify the host is actually functional and that VMM isn’t reporting problems due to the host being offline. You may find the system’s performance may be compromised, indicating an issue.
Now that you’re done with the basics, let’s move on to other things you can check to give your computer the attention it needs.
Beyond Basics for Host Needs Attention Problems
Let’s discuss 4 more actions you can take to fix the “Host Needs Attention” problems in VMM.
1. Check the VMM RunAs Account is a Member of the Administrators Group
The next thing you should do is to log onto the host and make sure the VMM RunAs account is a member of the local Administrator’s group. Keep in mind that the account might not be named RunAs.
To verify the RunAs account is in proper use:
- Open the VMM management console.
- Select the Settings workspace.
- Select the RunAs Accounts tab. (the available RunAs accounts will appear)
- Record the names of the RunAs accounts in your system. (the following image shows you how it looks for the RunAs accounts my VMM server is using)
RunAs is an administrator; no problem here! - Log in to the host that VMM is having problems with.
- Open the Computer Management console.
- Navigate through the console to Computer Management > System Tools > Local Users and Groups > Groups.
- Open the Administrators group and make sure at least one VMM RunAs account you noted before is in the list. (Check the figure below for an example)
Now, the VMM RunAs account is included in the Administrators group.
2. Verify the VMM Agent’s Presence
VMM uses an agent to manage hosts, and a malfunctioning host is often a symptom of a problem with an agent. To verify the agent is still installed on the host server:
- Log in to the host and open the Control Panel.
- Click on Programs, followed by Uninstall a Program.
- Look through the list of installed programs to make sure the Microsoft System Center Virtual Machine Manager Agent is on the list.
The Microsoft System Center Virtual Machine Manager DHCP Server and Microsoft Visual C++ Redistributable should also be present, as shown in the figure below.

3. Check the Firewall
It’s also important to make sure firewall rules aren’t preventing the VMM agent from communicating with the VMM server. At a minimum, you’ll need to allow WinRM communications over port 5985 and HTTPS communications on port 443. You’ll also need to check all firewalls between your VMM server and the host server.
4. Ensure the Required Services Are Running
For VMM to properly manage a Hyper-V host, the WinRM service must be running on the host server. To that end:
- Open PowerShell and run the following command: Get-Service WinRM
- Make sure the service’s status appears as Running.
- Start the service using the following command: Start-Service WinRM (in case it isn’t Running)
The following figure shows the process to check and start the WinRM service.

It’s worth noting that other system services are probably present that depend on the WinRM service. If the WinRM service has stopped, then any dependency services will also have stopped. Simply restarting the WinRM service won’t cause dependency services to start. The easiest way to check for services that have stopped is to:
- Enter the following command into PowerShell: Get-Service | Where-Object {($_.Status -eq ‘Stopped’) -and ($_.StartType -eq ‘Automatic’)}.
- Repeat the command and append a pipe symbol ‘|’ and the Start-Service cmdlet if the command returns a service list.
Keep in mind that some services configured to start automatically are designed to stop if they’re not in use. In the case of the figure below, though, you can see the System Center Virtual Machine Manager agent is among the services that aren’t running.

Pro Tip
One last bit of advice is that it’s a good idea to check for stopped services, even if the WinRM service hasn’t failed. That’s because it’s possible for the VMM Agent service to stop, even if the WinRM service is running.
Final Thoughts
Ultimately, any number of reasons can cause a managed host to stop responding. If you’re having problems, make sure your server clocks are in sync. You also can check that your DNS records are correct and your host is online. If all those things check out, then you’ll need to delve into other troubleshooting steps, like verifying that the agent is installed. Ensure the WinRM service is running, no firewall ports are blocked, and your RunAs account is a member of the local administrator group.
FAQs
Does the VMM agent service have any additional dependencies?
The VMM agent depends on the following services: Background Intelligent Transfer Service (BITS), WinRM, and WinMGMT. BITS manages data between the physical and virtual environments. WinRM handles transactions between servers and clients. WinMGMT manages client data, essentially parsing data to the user’s terminal.
A Hyper-V host has been previously managed by a different VMM server, but I am unable to manage it with a new VMM server?
A host server can only be managed by a single host. If you need to manage a host using a different VMM server, you can either remove and reinstall or reassociate the agent. The easiest way to remove the agent is to select the agent from the Control Panel (step 2 in this article) and click Remove.
I keep having problems with clocks drifting out of sync. How can I stop this from happening?
You can have multiple reasons why clock skew happens. You can find tips for fixing this problem here. Issues include clients working in different time zones, hosting from different sites, and a manual time override on a client machine.
What is the WinRM service and why does it need to be running?
WinRM is the Windows Remote Management Service. It’s the protocol that VMM uses to interact with Hyper-V hosts and other infrastructure components. If this service isn’t running, a remote terminal won’t be able to connect and use either the CLI or graphical connection to the server through the Simple Object Access Protocol (SOAP).
What is the difference between the System Center Virtual Machine Manager service and the System Center Virtual Machine Manager Agent service?
The System Center Virtual Machine Manager Agent service corresponds to the VMM agent. This service runs on the VMM server and on any managed hosts. The System Center Virtual Machine Manager service corresponds to VMM itself and only runs on the VMM server.
Resources
Microsoft Support Ports Article
Discover the ports that VMM uses here.
Microsoft Host Management Documentation
Read more on how to resolve issues with host management in the official Microsoft documentation.
Microsoft Time Settings
Learn about dealing with Windows clock skew issues here.
Windows Remote Management Article
Read about WinRM here to help you understand how Windows Remote Management works.
Adding Hosts to VMM
Find out what to do if you have trouble adding VMM hosts here.