The Case Of… Windows 7 Network Connections empty folder

Well... this is not an Identity Management specific post, but I would like to make my blog more content wide and cover other areas of work and experience, so here it goes the first non-Identity post :).

For some unknown reason, it happened to me that my “Network Connections” folder in Windows 7 x64 got empty., Network connections all still work, and I could even go and change some settings through netsh, but I was commited to fix the issue. Hitting refresh button updated the status line of the window with “0 connections” message.

After some “Bingging” ;-), I found similar issues and fixes for XP both in Microsoft Support Knowlege Base and some forums that were not applicable.

System reboots, updating network drivers, removing and adding interfaces in Device Manager, removing network services related stuff such as network virtualization bridges, re-registering netshell.dll, netcfgx.dll and netman.dll, adding Network Service account to Local Administrators group (this one fixed another “Network and Sharing Center” empty screen issue in the past) were not helpful neither.

Normally system restore points will have being really helpful here, but due to lack of disk space, I had not enough restore points to get back to a healthful state, specially after last three Windows Update packages came through.

So after several hours and system reboots I was almost ready to give up when I decided to give Process Monitor and myself a last chance before rebuilding my system. I added svchost.exe and svchost.exe’s instance that holds “Network Connections” service (NetMan) in ProcMon filters, like this:

image

I just got the needed svchost.exe instance PID by looking for Netman service in Process Explorer tooltip, like this:

image

Then I looked at registry calls when hitting refresh button in ncpa.cpl window (that is how you can launch “Network Connections” dialog quickly) and comparing it with the same activity in a healthy system.

While the healthy system registry activity queried for NIC information in the registry, my faulty system was giving a BUFFER OVERFLOW result when quering for HKLM\SYSTEM\CurrentControlSet\Control\Network\Connections\ClassManagers value. A simple look to this value seems fine, but when I edited it I just found that for some reason the faulty system had all 4 GUIDs ({B4C8DF59-D16F-4042-80B7-3557A254B7C5},{BA126AD3-2166-11D1-B1D0-00805FC1270E},{BA126AD5-2166-11D1-B1D0-00805FC1270E} and {BA126ADD-2166-11D1-B1D0-00805FC1270E}) in a single line, instead of in separate lines of this REG_MULTI_SZ value as it should be.

So just fixing the REG_MULTI_SZ value to a proper format and hitting refresh in “Network Connections” dialog made network connection icons come back again!

Hope this helps.