Can't add users in message delivery restrictions for distribution group on Exchange 2010

In my case there were active directory and mailbox disabled users, that were listed as allowed senders for distribution group. When tried to add new users as allowed senders for distribution group, there was error message:

Error: Couldn't find object "domain/ou/disabled user". Please make sure that it was spelled correctly or specify a different object.
Resolution for this problem is to remove disabled users as allowed senders, which can't be seen from Exchange Management Console 2010. One way to do that is to enable advanced feature in active directory users and computer console and edit the authOrig attribute from Attribute Editor. Remove all disabled accounts, refresh Exchange Management Console and you will be able to add new users as allowed senders for distribution group.

Enabling ipv6 on Windows Server 2003 DNS

IPv6 is not by default enabled on Windows Server 2003, installing ipv6 can be done from control panel (Network Connections -> Properties -> Install -> Protocol -> Add -> Microsoft TCP/IP version 6) . Assigning manual IPv6 address is not possible via GUI, so we'll use netsh :

netsh interface ipv6 add address [interface=]string [address=]ipv6address
for example: netsh interface ipv6 add address interface="Local Area Connection" address=2001:520:432:cafe::543

You can view ipv6 routing table using :
netsh interface ipv6 show routes
Adding gateway for this network interface can be done also with netsh, for example:
netsh interface ipv6 add route ::/0 "Local Area Connection" 2001:520:432:cafe::1

To configure DNS to listen over IPv6, install Windows Support Tools from installation cd rom from \Support\Tools\suptools.msi. Execute:
dnscmd /config /EnableIPv6 1
and restart the DNS service.

Using nslookup you can test the functionality of the DNS

Unable to delete printer driver from Windows 7

In my case user was running on windows 7 x86 sp1, and was complaining that he can't print because printers doesn't exists on his computer. Printers should be installed using group policy preferences, so I have started to troubleshoot the problem. Printer spooler was stopped, and that was the reason why the user doesn't see printers in control panel. Printer spooler was stopping whenever group policy for installing printers was applying. So, I wanted to delete all unnecessary printer drivers that were installed. After opening Print Management mmc there were a lot of printers drivers that were not in use, and I started to remove drivers packages that were not in use. For the most of them removing was running smoothly, but there was one that was refusing to delete complaining that :

"The specified printer driver is currently in use. Failed to remove package ..."
I have tried a lot of the suggested solutions, but none of them helped me to delete the driver package. The only way that I have succeeded to delete the driver package was to rename the print processor from registry in my case HKLM\SYSTEM\CurrentControlSet\Control\Print\Environments\Windows NT x86\Print Processors\ , and then delete the driver package from print management console.
Printers defined in GPO have successfully installed, and user was able to print documents.

Unable to reboot remote system

In my case remote workstation was XP and a user was unable to connect using remote desktop client, after disconnecting from the same computer couple of minutes ago. I have decided to initiate reboot of the client workstation using:
shutdown /f /r /m \\computername,
but the machine was hung up, and I tried to initiate same command again but the response was :
A system shutdown is in progress.(1115)
 
After waiting few more minutes the client workstation was not rebooted.
Because there was no one around the client machine to see what's happening on the monitor, and the user desperately needed to establish remote connection to the client workstation I have decided to kill the winlogon process. Using PSKill from PSTools suite I have executed:
pskill -t \\computername winlogon

and the remote workstation was rebooted. Note that killing winlogon process is nearly the same as pulling the plug on the machine.

How to check EMBG (Unique Master Citizen Number) using regex

In this post, I will share my implementation of how to check if some number looks like EMBG or Unique Master Citizen Number. For those of yo...