Windows Management Instrumentation :
Windows Management Instrumentation is a core Windows management technology; you can use WMI to manage both local and remote computers. WMI provides a consistent approach to carrying out day-to-day management tasks with programming or scripting languages. For example, you can:
• Start a process on a remote computer.
• Schedule a process to run at specific times on specific days.
• Reboot a computer remotely.
• Get a list of applications installed on a local or remote computer.
• Query the Windows event logs on a local or remote computer.
The word "Instrumentation" in WMI refers to the fact that WMI can get information about the internal state of computer systems, much like the dashboard instruments of cars can retrieve and display information about the state of the engine. WMI "instruments" by modeling objects such as disks, processes, or other objects found in Windows systems. These computer system objects are modeled using classes such as Win32_LogicalDisk or Win32_Process; as you might expect, the Win32_LogicalDisk class models the logical disks installed on a computer, and the Win32_Process class models any processes currently running on a computer. Classes are based on the extensible schema called the Common Information Model (CIM). The CIM schema is a public standard of the Distributed Management Task Force (http://www.dmtf.org).
WMI capabilities also include eventing, remoting, querying, views, user extensions to the schema, instrumentation, and more.
Start a process on a remote computer.
Schedule a process to run at specific times on specific days.
Reboot a computer remotely.
Get a list of applications installed on a local or remote computer.
Query the Windows event logs on a local or remote computer.
Microsoft's WMI (Windows Management Instrumentation) diagnosis utility
Microsoft has released a new diagnosis tool that helps system administrators diagnose and repair problems with the WMI. It is advisable to go through the WMIDiag_ReadMe.doc file to understand how the utility works, and the supported command-line arguments. Here is the download link: The WMI Diagnosis Utility
You may use the utility (WMIDiag.vbs) to find if a repository rebuild is necessary or not. The utility runs a comprehensive testing of WMI and reports the results to a log file, which is placed in the user's Temp folder (%Temp%) folder by default.
Mr. Alain Lissoir [MS] was kind enough to share the following info with me:
If there is a need among all problems detected by WMIDiag to rebuild the repository after attempting all fix suggested by WMIDiag, WMIDiag will list the rebuild of the repository as the last action among thing that can be done (before rebuilding the repository).
Rebuilding the WMI Repository
If you experience behavior when using WMI, such as application errors or scripts that used to work are no longer working, you may have a corrupted WMI repository. To fix a corrupted WMI repository, use these steps:
Windows XP and Windows Vista
Click Start, Run and type CMD.EXE
Note: In Windows Vista, you need to open an elevated Command Prompt window. To do so, click Start, click All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator.
Type this command and press Enter:
net stop winmgmt
Using Windows Explorer, rename the folder %windir%\System32\Wbem\Repository. (For example, %windir%\System32\Wbem\Repository_bad). %windir% represents the path to the Windows directory, which is typically C:\Windows.
Switch to Command Prompt window, and type the following and press ENTER after each line:
net start winmgmt
EXIT
Click Start, Run and type the following command:
rundll32 wbemupgd, UpgradeRepository
This command is used to detect and repair a corrupted WMI Repository. The results are stored in the setup.log (%windir%\system32\wbem\logs\setup.log) file.
For Windows Vista
Open an elevated Command Prompt window. To do so, click Start, click All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator.
Type the following command:
winmgmt /salvagerepository
The above command Performs a consistency check on the WMI repository, and if an inconsistency is detected, rebuilds the repository. The content of the inconsistent repository is merged into the rebuilt repository, if it can be read.
For Windows Server 2003
Use the following command to detect and repair a corrupted WMI Repository:
rundll32 wbemupgd, RepairWMISetup
Re-registering the WMI components
The .DLL and .EXE files used by WMI are located in %windir%\system32\wbem. You might need to re-register all the .DLL and .EXE files in this directory. If you are running a 64-bit system you might also need to check for .DLLs and .EXE files in %windir%\sysWOW64\wbem.
To re-register the WMI components, run the following commands at the command prompt:
- cd /d %windir%\system32\wbem
- for %i in (*.dll) do RegSvr32 -s %i
- for %i in (*.exe) do %i /RegServer
Note that none of the above two methods restore the missing files related to Windows Management Instrumentation (WMI). So, below is a comprehensive repair procedure that restores all the missing WMI modules. In case of missing WMI modules, you may use the following method.
Comprehensive rebuild method
Important note: If you've installed a Service Pack, you need to insert your Windows XP CD with Service Pack integration (called as the Slipstreamed Windows XP CD). If you don't have one, you may point to the %Windir%\ServicePackFiles\i386 folder for a recent version of the system files required during WMI repair. Or you may create a slipstreamed Windows XP CD and insert it when prompted.
Click Start, Run and type the following command, and press ENTER:
rundll32.exe setupapi,InstallHinfSection WBEM 132 %windir%\inf\wbemoc.inf
Insert your Windows XP CD into the drive when prompted. Repair process should take few minutes to complete. Then restart Windows for the changes to take effect.
Arun Sabale | L2 tech
Zenith Infotech Ltd.
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