#PSTip Get a list of all Com objects available

Note: This tip requires PowerShell 2.0 or above.

Recently a question was posted on the PowerShell.com forums: How to get a full list of available ComObjects? This tip will show how fetch all of them from the registry.

Here is the code that we can use to generate this list:

Get-ChildItem HKLM:\Software\Classes -ErrorAction SilentlyContinue | Where-Object {
	$_.PSChildName -match '^\w+\.\w+$' -and (Test-Path -Path "$($_.PSPath)\CLSID")
} | Select-Object -ExpandProperty PSChildName

The first Cmdlet reads out a complete list of values from HKLM:\Software\Classes and then verifies if the following two conditions are true:

• Does the object match the naming convention for a ComObject?
• Does the registry key have a CLSID folder? Every registered ComObject should have a CLSID as a unique identifier.

An example of the output generated by this command is as follows:

AccClientDocMgr.AccClientDocMgr
AccDictionary.AccDictionary
Access.ACCDAExtension
Access.ACCDCFile
Access.ACCDEFile
Access.ACCDTFile
Access.ACCFTFile
Access.ADEFile

To make the process of discovering ComObject easier the following function can be used.

function Get-ComObject {
    param(
        [Parameter(Mandatory=$true,
        ParameterSetName='FilterByName')]
        [string]$Filter,

        [Parameter(Mandatory=$true,
        ParameterSetName='ListAllComObjects')]
        [switch]$ListAll
    )

    $ListofObjects = Get-ChildItem HKLM:\Software\Classes -ErrorAction SilentlyContinue | Where-Object {
        $_.PSChildName -match '^\w+\.\w+$' -and (Test-Path -Path "$($_.PSPath)\CLSID")
    } | Select-Object -ExpandProperty PSChildName

    if ($Filter) {
        $ListofObjects | Where-Object {$_ -like $Filter}
    } else {
        $ListofObjects
    }
}

This function is available in the TechNet Script Gallery:

http://gallery.technet.microsoft.com/Get-ComObject-Function-to-50a92047