Managing Windows Networks Using Script -- Part 13: the Script

This updated guide examines Managing Windows Networks Using Script -- Part 13: the Script and organizes the essential facts, background, and practical takeaways in clear American English.

Mitch Tulloch

In the previous article of this series we came up with a script called DisplayClassProperties.vbs, which shows the names of the properties of the WMI class.This is what the script content is, by using Win32_BootConfiguration as a class, we are connecting to the WMI nickname :

Option Explicit On Error Resume Next Dim strComputer Dim strWMINamespace Dim strWMIQuery Dim objWMIService Dim colItems Dim objItem strComputer = "." strWMINamespace = "rootCIMV2" strWMIQuery = ": Win32_BootConfiguration" Set objWMIService = GetObject ("winmgmts:" & strComputer & strWMINamespace & strWMIQuery) WScript. Echo "Number of properties of" & strWMIQuery & "class is" & objWMIService. Properties_.count For Each objItem in objWMIService. Properties_ Wscript. Echo "Property:" & objItem.name next

When running this script (using local administrative information) on a Windows XP computer (with Cscript.exe previously configured as a default Windows script), the results are as follows:

C: scripts> DisplayClassProperties.vbs Microsoft (R) Windows Script Host Version 5.6 Copyright (C) Microsoft Corporation 1996-2001. All rights reserved. Number of properties of: Win32_BootConfiguration class is 9 Property: BootDirectory Property: Caption Property: ConfigurationPath Property: Description Property: LastDrive Property: Name Property: ScratchDirectory Property: SettingID Property: TempDirectory

As mentioned in the last section, this script can easily be customized to display the attribute name of any WMI class. For example, if you want to display all property names in the Win32_DiskPartition class, we just need to change the line:

strWMIQuery = ": Win32_BootConfiguration"

into:

strWMIQuery = ": Win32_DiskPartition"

When running the script again, the result will be:

C: scripts> DisplayClassProperties.vbs Microsoft (R) Windows Script Host Version 5.6 Copyright (C) Microsoft Corporation 1996-2001. All rights reserved. Number of properties of: Win32_DiskPartition class is 34 Property: Access Property: Availability Property: BlockSize Property: Bootable Property: BootPartition Property: Caption Property: ConfigManagerErrorCode Property: ConfigManagerUserConfig Property: CreationClassName Property: Description Property: DeviceID Property: DiskIndex Property: ErrorCleared Property: ErrorDescription Property: ErrorMethodology Property: HiddenSectors Property: Index Property: InstallDate Property: LastErrorCode Property: Name Property: NumberOfBlocks Property: PNPDeviceID Property: PowerManagementCapabilities Property: PowerManagementSupported Property: PrimaryPartition Property: Purpose Property: RewritePartition Property: Size Property: StartingOffset Property: Status Property: StatusInfo Property: SystemCreationClassName Property: SystemName Property: Type

Displays the values of each attribute

Here we go back to using Win32_BootConfiguration as a class, if changed so that the script will list not only the names of all properties but also their values, you only need to change the line:

Wscript. Echo "Property:" & objItem.name

into:

Wscript. Echo "Property:" & objItem.name & vbTab & "Value:" & objItem.value

Results when running:

C: scripts> DisplayClassProperties.vbs Microsoft (R) Windows Script Host Version 5.6 Copyright (C) Microsoft Corporation 1996-2001. All rights reserved. Number of properties of: Win32_BootConfiguration class is 9 Property: BootDirectory Value: Property: Caption Value: Property: ConfigurationPath Value: Property: Description Value: Property: LastDrive Value: Property: Name Value: Property: ScratchDirectory Value: Property: SettingID Value: Property: TempDirectory Value:

The results are all empty. Why is that?

This is what is going on, take a look at this line:

Set objWMIService = GetObject ("winmgmts:" & strComputer & strWMINamespace & strWMIQuery)

Including the values of each variable we can record this line as follows:

Set objWMIService = GetObject ("winmgmts:.rootCIMV2: Win32_BootConfiguration")

Note that we are connecting to a specific WMI class (Win32_BootConfiguration) in the WMI nickname to be able to return a set of properties of this class. We then want to display the name and value of each attribute. But the values returned NULL are because they are not connected to the specific nstance of this class. WMI Glossary says that an instance is 'an instance of the real world that has managed an object with a specific class' and ' instances include real values' and this real value is what we want. So how can you connect to an instance of a class?

To connect to an instance of a class, you need to specify a separate instance by using the key property of the class. We can see that the key property is an attribute that provides the identifier needed for an instance of the class and the key properties are marked with a Key qualifier in the MSDN documentation. Take a look at the MSDN page about configuring the Win32_BootConfiguration class to know more about the key property for this class. Figure 1 shows a section of this page, showing you how to distinguish the key property of the class:

Figure 1: Key property for Win32_BootConfiguring class

From this MSDN page, we can see that the key property for the Win32_BootConfiguration class is Name. This means that we need to specify a value for this attribute in the WMI alias string if we want to connect to a specific instance of the class to get the values of each class attribute. In other words, all you need to do is change the line:

strWMIQuery = ": Win32_BootConfiguration"

into:

strWMIQuery = ": Win32_BootConfiguration. Name = 'SOMETHING'"

At 'SOMETHING' is the attribute value name of a specific instance in the class.

How can we find the value of the key property of a specific instance of the class? One way is to use Windows Management Instrumentation Tester (wbemtest.exe). Start by typing wbemtest at the command window so you can open the window as follows:

Figure 2: Windows Management Instrumentation Tester

Click the Connect button and connect to the rootcimv2 namespace:

Figure 3: Connect to the Win32_BootConfiguration class

Click Connect to return to the main window, where all the buttons are displayed here:

Figure 4: Connected to class

Click the Enum Instances button and type the class name to display all instances of the class:

Figure 5: Displaying instances of the class

Finally, click OK to display all instances of the class as listed by their key property (Name):

Figure 6: Instances of Win32_BootConfiguration

After all has been removed, there is only one instance of this class on the computer and the Name attribute of this instance has the value "BootConfiguration"! this means that to display the values of the properties of the instance of the Win32_BootConfiguration class on our computer, all that's needed is to change this line:

strWMIQuery = ": Win32_BootConfiguration"

into:

strWMIQuery = ": Win32_BootConfiguration. Name = 'BootConfiguration'"

Alternatively, the DisplayClassProperties.vbs script is reviewed now as follows:

Option Explicit On Error Resume Next Dim strComputer Dim strWMINamespace Dim strWMIQuery Dim objWMIService Dim colItems Dim objItem strComputer = "." strWMINamespace = "rootCIMV2" strWMIQuery = ": Win32_BootConfiguration. Name = 'BootConfiguration'" Set objWMIService = GetObject ("winmgmts:" & strComputer & strWMINamespace & strWMIQuery) WScript. Echo "Number of properties of" & strWMIQuery & "class is" & objWMIService. Properties_.count For Each objItem in objWMIService. Properties_ Wscript. Echo "Property:" & objItem.name & vbTab & "Value:" & objItem.value next

When running this script, it will not only display the names of the properties but also their values:

C: scripts> DisplayClassProperties.vbs Microsoft (R) Windows Script Host Version 5.6 Copyright (C) Microsoft Corporation 1996-2001. All rights reserved. Number of properties of: Win32_BootConfiguration. Name = 'BootConfiguration' class is 9 Property: BootDirectory Value: WINDOWS Property: Caption Value: DeviceHarddisk0Partition1 Property: ConfigurationPath Value: WINDOWS Property: Description Value: DeviceHarddisk0Partition1 Property: LastDrive Value: C: Property: Name Value: BootConfiguration Property: ScratchDirectory Value: C: WINDOWSsystem32configsystemprofileLocal SettingsTemp Property: SettingID Value: Property: TempDirectory Value: C: WINDOWSsystem32configsystemprofileLocal SettingsTemp

Put this information in the table for easier reading:

BootDirectory

WINDOWS

Caption

DeviceHarddisk0Partition1

ConfigurationPath

WINDOWS

description

DeviceHarddisk0Partition1

LastDrive

C:

Name

BootConfiguration

ScratchDirectory

C: WINDOWSsystem32configsystemprofileLocal SettingsTemp

SettingID

Value:

TempDirectory

C: WINDOWSsystem32configsystemprofileLocal SettingsTemp

Conclude

We can see that this simple 'return all values' script gave us useful information about the computer. Here's an exercise you can do yourself: instead of connecting to an instance of the Win32_BootConfiguration class (there is only one instance of this class), try to connect to an instance of the Win32_DiskPartition class (the class has a few instance if your computer has multiple partitions. To do that, you first need to use wbemtest to display instances of this class (learn more about the other key property with these instances) and then change the DisplayClassProperties.vbs script so it can display attributes and values of a specific instance of this class (ie the disk partition you specified).

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FAQ

What is Managing Windows Networks Using Script -- Part 13: the Script about?

It provides a structured overview of property, explains the main context, and highlights practical takeaways for readers.

Why does this topic matter?

Understanding the main concepts helps readers evaluate the issue, avoid common mistakes, and make better-informed decisions.

How should readers use this information?

Use the guidance as a practical starting point, confirm details that may have changed, and follow current product, safety, or security recommendations.