The result is that I cannot change any drivers or devices.

The solution is very simple but not obvious. My computer name is longer than 15 characters. This is a problem for NetBIOS computers. It turns out this is also a problem for the device manager. So I changed my computer name to a name with less than 15 characters, now everything works normal again.

The first one I tried in my own lab was the one that Daniel Petri describes in het Blog post at: http://www.petri.co.il/reset_domain_admin_password_in_windows_server_2003_ad.htm

There were some requirements for this trick.

• Local access to the domain controller (DC).
• The Local Administrator password.
• Two tools provided by Microsoft in their Resource Kit: SRVANY and INSTSRV. Download them from HERE (24kb).

The first one was no problem, but the second one in my case was a problem, we didn’t no the local administrator password.

So this is how I did it, first of all download the DART tools (Diagnostics and Recovery Toolset) from the Microsoft website, this is available for MDOP License owners. See http://www.microsoft.com/windows/enterprise/products/mdop/dart.aspx

There are other ways to get your hands on this tool, go to the Technet site and get a Technet Subscription. And if you don’t have access to both sources, go search Google.

I restarted the domain domain controller, and boot into the DART tool. Go to the Locksmith tool, and reset the password of the Administator account. Reboot the server, in Active Directory Recovery mode. This is important because now the Local accounts are available for logon. The local accounts are disabled on a Domain Controller, this is by design. In recovery mode logon with your new local Administrator password. Now do the trick that Daniel Petri describes in his post.

This is how it works globally.

Step 1

Restart Windows 2003 in Directory Service Restore Mode.

Note: At startup, press F8 and choose Directory Service Restore Mode. It disables Active Directory. When the login screen appears, log on as Local Administrator. You now have full access to the computer resources, but you cannot make any changes to Active Directory.

Step 2

You are now going to install SRVANY. This utility can virtually run any programs as a service. The interesting point is that the program will have SYSTEM privileges (LSA) (as it inherits the SRVANY security descriptor), i.e. it will have full access on the system. That is more than enough to reset a Domain Admin password. You will configure SRVANY to start the command prompt (which will run the ‘net user’ command).

Copy SRVANY and INSTSRV to a temporary folder, mine is called D:\temp. Copy cmd.exe to this folder too (cmd.exe is the command prompt, usually located at %WINDIR%\System32).

Start a command prompt, point to d:\temp (or whatever you call it), and type:

instsrv PassRecovery "d:\temp\srvany.exe"

(change the path to suit your own).

It is now time to configure SRVANY.

Start Regedit, and navigate to

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\PassRecovery

Create a new subkey called Parameters and add two new values:

name: Application

type: REG_SZ (string)

value: d:\temp\cmd.exe

name: AppParameters

type: REG_SZ (string)

value: /k net user administrator 123456 /domain

Replace 123456 with the password you want. Keep in my mind that the default domain policy require complex passwords (including digits, respecting a minimal length etc) so unless you’ve changed the default domain policy use a complex password such as P@ssw0rd

Now open the Services applet (Control Panel\Administrative Tools\Services) and open the PassRecovery property tab. Check the starting mode is set to Automatic.

Go to the Log On tab and enable the option Allow service to interact with the desktop.

Restart Windows normally, SRVANY will run the NET USER command and reset the domain admin password.

Step 3

Log on with the Administrator’s account and the password you’ve set in step #2.

Use this command prompt to uninstall SRVANY (do not forget to do it!) by typing:

net stop PassRecovery

sc delete PassRecovery

Now delete d:\temp and change the admin password if you fancy.

Done!

Test Lab Guides

Customers often ask “Given a hardware load-out X, how many Ys can I get/run/host?”

The frustrating answer always starts with “…it depends…”. We caveat this way not because we want to frustrate, but because it is true. Many teams will go on to say “We have tested the following in our labs and gotten the displayed results…”

1 X = thingy

2 X = more thingies

3X = many more thingies

While accurate, not super-helpful.

The truth is that to do good perf planning for Hyper-V you have to run some tests.

Run them using your actual production load (converted to Virtual Machines) in a test environment.

TIP: you can download the free VHD version of SCVMM, then run it as a VM to convert your production machines to “test” virtual machines.

Then play with your assumptions and tweak things higher and lower and to your design tolerance and actually observe how perf goes.

Add an overhead/forgot-to-test percentage, done.

So, how to do that for Hyper-V? Here are some perf testing resources to help you:

• Performance and capacity requirements for Hyper-V
• Hyper-V Performance FAQ
• Measuring Performance on Hyper-V
• Checklist: Measuring Performance on Hyper-V
• Performance Tuning Guidelines for Windows Server 2008
• Performance Testing Guide for Windows Paper
• Optimizing Hyper-V performance: Advanced fine-tuning
• Hyper-V Support, Performance and Load Tools
• Hyper-V How To: Set Up a Virtualization Test Lab using Windows Server 2008 Cluster, Hyper-V and simulated iSCSI…
• Hyper-V Server Sizing: How Much Memory for the Host?
• VM Perftuning: Minimize VM background processing
• Hyper-V How To: Balance VM I/O
• Monitoring Hyper-V Performance
• How to get Processor Utilization for Hyper-V via WMI
• Hyper-V Performance Counters – Part one of many – The overview
• Hyper-V Performance Counters – Part two of many – “Hyper-V Hypervisor” counter set
• Hyper-V Performance Counters – Part three of many – “Hyper-V Hypervisor Logical Processors” counter set
• Hyper-V Performance Counters – Part four of many – “Hyper-V Hypervisor Virtual Processor” and “Hyper-V Hypervisor Root Virtual Processor” counter set
• Hyper-V Performance Counters – Part five of many – “Hyper-VM VM Vid Numa Node