Howto manually backing up and restoring the vCenter Server 4.x ADAM instance data

Please read the following article from VMware KB

Unable to create snapshots on Windows guest operating systems

Creating a snapshot (including the memory state) of a virtual machine on Windows fails
You see the error:
Cannot create a quiesced snapshot because the create snapshot operation exceeded the time limit for holding off I/O in the frozen virtual machine
The VMware Snapshot Provider service does not get installed when installing VMware Tools
Uninstalling and re-installing VMware Tools does not resolve this issue
This issue can occur on Windows 2003 and 2008 operating systems if the VMware Snapshot Provider does not get installed.
To work around this issue manually register the VMware Snapshot Provider:
Click Start > Run, type cmd, and click OK.
Enter these commands, in sequence:
regsvr32 "C:\Program Files\VMware\VMware Tools\Drivers\vss\VCBRequestor.dll"
regsvr32 "C:\Program Files\VMware\VMware Tools\Drivers\vss\VCBSnapshotProvider.dll"
"C:\Program Files\VMware\VMware Tools\COMREG.EXE" -register "C:\Program Files\VMware\VMware Tools\Drivers\vss\VCBSnapshotProvider.dll" "VMware Snapshot Provider" "vmvss" "VMware Snapshot Provider"
For more information read this article from VMware KB.

How to restore the default vCenter Server alarms

To restore the default vCenter Server alarms, you must remove all existing alarm definitions in vCenter Server and then set the value of alarm.version to 0.
To delete all the existing alarm definitions in the vCenter Server:

•     Log in to the vCenter Server using the vSphere Client.
•     Click the Hosts and Clusters view.
•     Click the Alarms tab.
•     Click Definitions.
•     Note: All custom alarms must be manually recreated after they are removed. Ensure to note the custom alarms before removing.
•     Select all alarms, right-click, and  click Remove.

To restore the default vCenter Server alarms, change the alarm version in vCenter Server:

•     Connect to vCenter Server using the vSphere Client.
•     Click Administration > vCenter Server Settings.
•     Click Advanced Settings.
•     Set alarm.version to 0.
•     Set alarms.upgraded to false
•     Restart the VMware VirtualCenter Server service.

For more information take a look at this VMware article.

How to reset domain admin password on a Windows Server 2008

1. Boot onto DVD of Windows Server 2008
2. Choose “Repair your computer”
3. Launch cmd
4. Go to c:\windows\system32
5. Rename Utilman.exe to Utilman.exe.bak
6. Copy cmd.exe to Utilman.exe
7. Reboot on Windows
8. Do the keyboard shortcut Windows + U when on the logon screen
9. net user administrator Newpass123 inside the cmd
10. log on with the domain admin account and this new pass
11. change the password to remember it if needed
12. Reboot on the DVD to put back the original Utilman.exe

For more info take a look at this link