Compare the Difference between two Group Policy Objects

Advanced Group Policy Management is a tool available in the Microsoft Desktop Optimization Pack that gives IT administrators a management platform for controlling change in Group Policy Objects.

You can think of this tool as source control for group policy objects.  There is a server component that stores GPO changes and proposed GPO changes in a central archive.  The client component integrates within the Group Policy Management Console and allows an administrator to edit, review, and enforce GPO change requests from other administrators.

If you have two group policies that are similar in nature but need to know how they differ, you can use Advanced Group Policy Management to generate a report that outlines the differences between two group policies.  Let’s see how this is done…

Advanced Group Policy Management incorporates a new icon in the Group Policy Management Console called Change Control.  In the Change Control window, locate the two group policies you’d like to compare.  Highlight both of them, and choose Differences | HTML Report from the right-click context menu.


The results of the HTML report shows the results of the comparison.  The top of the report lists the two group policies under consideration.  The policy on top is known by convention as the first GPO and the policy on the bottom is called the second GPO.



Items that exist in the first GPO are outlined by a [-] symbol and are highlighted red.  Items that exist in the second GPO are outlined by a [+] symbol and are highlighted green. Items that exist in both GPOs but have different settings are outlined by a [#] symbol and are highlighted blue.




DFS was configured and working fine on Server 2008 STD, but now it’s no longer replicating.

- Due to the following error, the DFS Replication reporting mechanism cannot access the WMI (Windows Management Instrumentation) namespace to retrieve certain reporting information. Error ID: 0x80041002.
- DFS Replication cannot replicate with partner <server name> for replication group <domain>\<name space>\<share>. The partner did not recognize the connection or the replication group configuration. The DFS Replication service used partner DNS name <server name>, IP address <the server ip>, and WINS address <server name> but failed with error ID: 9026 (The connection is invalid). Event ID: 5012
- The DFS Replication service is stopping communication with partner <server name> for replication group Domain System Volume due to an error. The service will retry the connection periodically. 
Additional Information: 
Error: 1726 (The remote procedure call failed.) 
Connection ID: 580D7FC3-873F-48CC-AFC1-73E96DFADCE2 
Replication Group ID: ACA5FC8A-AA2E-4D40-8ECC-3A0A8F45E5F

Solution below sorted my problem:

Open a CMD prompt in %windir%\system32\wbem

type mofcomp dfsrprovs.mof as below

C:\Windows\System32\wbem> mofcomp dfsrprovs.mof
net stop winmgmt
net start winmgmt
net start iphlpsvc
net stop dfsr
net start dfsr

Fixing a DFSR connection problem

This happened for a replication group that is 1.6TB in size, so the volume check takes quite a long time.
During this time, replication hung so I decided to restart the DFSR service on our hub server. Unfortunately, the restart failed, and the service was hung at “stopping”. So I killed the dfsrs.exe process, and then started the service.

At this point, it tried to repair the DFSR database, but failed so it went into “initial replication”. Initial replication on a 1.6 TB replication group is a thing straight from my nightmares. Compounding the problem is the fact that the hub server then crashed the next night (which I haven’t had time to look into yet) and basically had to restart the process.

That was 3 days ago, and after all this time, I’ve got initial replication finished but a backlog of 10,000 files going to 2 of the spoke servers. That backlog didn’t appear to be moving, and investigating the DFS Replication section of the Event Log revealed:

The DFS Replication service encountered an error communicating with partner SW3020 for replication group\files\jobs. 
The service will retry the connection periodically. 
Additional Information: 
Error: 9032 (The connection is shutting down)


The steps I took to fix this error:

  • On the hub server, I deleted the individual connections from the hub to the spoke servers for this specific replication group
  • From a domain controller in the hub site, I ran this to ensure those changes reached the branch sites sooner:
    repadmin /syncall /e /A /P
  • Then I re-created the connections for each spoke and re-ran the repadmin command.

Following that, both servers showed this in the DFSR log:

The DFS Replication service failed to communicate with partner SW3020 for replication group\files\jobs. The partner did not recognize the connection or the replication group configuration. 
The service will retry the connection periodically. 
Additional Information: 
Error: 9026 (The connection is invalid)


So from each spoke server, I ran the following:

dfsrdiag pollad /v /         (Replication partner)
dfsrdiag pollad /v /      (Domain Controller in hub site)


Shortly thereafter I saw this in the logs:

The DFS Replication service successfully established an inbound connection with partner SW3020 for replication group\files\jobs.


And now replication traffic is flowing properly. Now all I have to do is deal with the more than 500 conflict files this whole ordeal has generated.

[FIX] Optical Drives (CD/DVD) Icon Not Showing in My Computer Window

Many times Windows users face strange problem when they can’t see the icon of optical drives (CD/DVD drives) in My Computer (also known as Windows Explorer or This PC) window. The drive icon doesn’t show in Explorer but the drive works fine in other computers.

If you are also facing this problem and can’t see your optical drives (CD/DVD Drives/Writers) in My Computer window, this tutorial will help you.

Simply follow the simple steps given in following methods to fix the problem:


1. Type regedit in RUN dialog box and press Enter. It’ll open Registry Editor.

2. Now go to following key:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\ {4D36E965-E325-11CE-BFC1-08002BE10318}


3. Look for “UpperFilters” and “LowerFilters” strings in right-side pane. If you find them, delete them.

4. Restart the system and now you should  have access to your optical drives.


If the above method doesn’t work for you or if you can’t see “UpperFilters” and “LowerFilters” keys in Registry, then following steps will help you:

1. Open Registry Editor and go to following key:


2. Create a new key Controller0 under atapi key.

3. Select the new Controller0 key and in right-side pane, create new DWORD EnumDevice1 and set its value to 1

3. Close Registry Editor and restart your system.

That’s it. Now you’ll be able to see your CD/DVD drive in My Computer window.


If the above mentioned method doesn’t work for you, you can directly add the DWORD in Registry by executing following command in Command Prompt:

reg.exe add “HKLM\System\CurrentControlSet\Services\atapi\Controller0” /f /v EnumDevice1 /t REG_DWORD /d 0x00000001

Make sure you open Command Prompt as Administrator as mentioned here.


If you don’t want to modify Registry yourself, download following ZIP file, extract it and you’ll get a ready-made Registry script which will modify Windows Registry automatically:

Download Registry Script to Fix CD/DVD Drive Missing in Windows


If the above mentioned methods don’t work for you, try following solution given by our reader “Vishal”:

1. Open Device Manager using devmgmt.msc command and enable “View -> Show hidden devices” option. Now locate the DVD/CD-ROM drives and IDE ATA/ATAPI controllers items.

2. Right-click on each entry present under both “DVD/CD-ROM drives” and “IDE ATA/ATAPI controllers” sections one bye one and select Uninstall.

3. Once all have been removed, right-click again and select Scan for hardware changes.

The drives will be rediscovered and when the drivers are loaded back, the drives will re-appear in My Computer window.

You can also try to restart your computer.

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