Microsoft support engineer, Mohamed Ameen, suggested I post this question/problem here.

I have a Windows 8.1 (64) PC that has a problem with a phantom or ghost Homegroup that is preventing it from becoming a part of a Homegroup on my home LAN. The Homegroup troubleshooter utility and all of the standard troubleshooting suggestions online have been of no help.

I found this thread ("http://answers.microsoft.com/en-us/windows/forum/windows_7-networking/homegroup-wont-go-away-ghost-group-on-whole/8a4f464f-e461-47aa-af05-07a4fd4875fd") which suggests replacing the Machinekeys folder, but it has very little in the way of instructions on how to completely perform the "repair" and/or the risks of causing other OS and program failures.

I have added additional information and screen shots to the thread I started on the Microsoft Community site and rather than repeating all of that I thought it would be easier to include a thread to that discussion: (http://answers.microsoft.com/en-us/windows/forum/windows8_1-networking/what-is-contained-in-the-machinekeys-folder/d7fb5189-e8c2-4ec8-ba2f-9e4e53905703 )

Hello

The MachineKeys folders store certificate pair keys for either or both the computer and users. Certificate services and Internet Explorer use this folder as examples.

https://msdn.microsoft.com/en-us/library/windows/desktop/bb204778(v=vs.85).aspx

https://msdn.microsoft.com/en-us/library/ee236869(v=bts.10).aspx

Hi,

For your problem, firstly, if you close the HomeGroup on Inspiron, then, restart both PC, will this same problem occurs? Please have a try. In addition, is XP PC has been created an HomeGoup? Please check it, this problem can be caused by XP system connect to your network.

If problem persists, access to XPS PC, open PC Settings, then click Network, check HomeGroup status.

1) The Machinekey folder trick didn't help my issue.

2) I realized at least part of the problem is an "orphaned" registry entry in HKLM\SYSTEM\CurrentControlSet\services\HomeGroupProvider\ServiceData.

I removed the Homegroup on the Inspirion and that registry key is empty with no homegroup created on that PC.

I tried to remove the key manually but no matter what I do Windows refuses to allow me to delete it (or any of the entries in the key). I can't change permissions either, even if I take ownership.

 

Hi,

For this problem, you can try to use Process Monitor the trace when creating HomeGroup on XPS PC, then find the reason of this problem.

You can access to the link below to download Process Monitor:

https://technet.microsoft.com/en-us/sysinternals/bb896645.aspx

How to capture a Process Monitor trace:

http://blogs.msdn.com/b/dswl/archive/2010/01/10/how-to-capture-a-process-monitor-trace.aspx

Learning Example:

Using Process Monitor to Troubleshoot and Find Registry Hacks:

http://www.howtogeek.com/school/sysinternals-pro/lesson5/all/

Note: Since the website is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.

For fun (actually it wasn't any fun at all :( ) I downloaded the Windows ADK and created a bootable Windows PE USB Stick. I then found that the orphaned key (and the entire HKLM/system/currentcontrolset) is apparently something Windows creates out of whole cloth and is not available to be edited or deleted offline.

Will using process monitor help trace the creation of this key?

Hello,

Currentcontrol set is generated when Windows loads, it is generated as a copy of the controlset001 in most cases.

This can be created from different control sets if controlset001 has issues.  this is controlled by a registry key.

Use this registry location to validate which control set is used to for current control set

HKLM\System\Select:Default

So in WinPE edit the controlset that the registry key points to