Working with software installations

Applications installed with the Windows Installer can be found through WMI's queries, but not all applications use the Windows Installer. The specific techniques for find applications installed with other tools depends on the installer software.

For example, applications installed by copying the files to a folder on the computer usually can't be managed using techniques discussed here. You can manage these applications as files and folders using the techniques discussed in Working With Files and Folders.

For software installed using an installer package, the Windows Installer can be found using the Win32Reg_AddRemovePrograms or the Win32_Product classes. However, both of these have problems. The Win32Reg_AddRemovePrograms is only available if you are using System Center Configuration Manager (SCCM). And the Win32_Product class can be slow and has side effects.

Caution

The Win32_Product class isn't query optimized. Queries that use wildcard filters cause WMI to use the MSI provider to enumerate all installed products then parse the full list sequentially to handle the filter. This also initiates a consistency check of packages installed, verifying and repairing the install. The validation is a slow process and may result in errors in the event logs. For more information seek KB article 974524.

This article provides an alternative method for finding installed software.

Querying the Uninstall registry key to find installed software

Because most standard applications register an uninstaller with Windows, we can work with those locally by finding them in the Windows registry. There is no guaranteed way to find every application on a system. However, it's possible to find all programs with listings displayed in Add or Remove Programs in the following registry key:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uninstall.

We can find the number of installed applications by counting the number of registry keys:

$UninstallPath = 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall'
(Get-ChildItem -Path $UninstallPath).Count

459

We can search this list of applications further using a variety of techniques. To display the values of the registry values in the registry keys under Uninstall, use the GetValue() method of the registry keys. The value of the method is the name of the registry entry. For example, to find the display names of applications in the Uninstall key, use the following command:

Get-ChildItem -Path $UninstallPath |
    ForEach-Object -Process { $_.GetValue('DisplayName') } |
    Sort-Object

Note

There is no guarantee that the DisplayName values are unique.

The following example produces output similar to the Win32Reg_AddRemovePrograms class:

Get-ChildItem $UninstallPath |
    ForEach-Object {
        $ProdID = ($_.Name -split '\\')[-1]
        Get-ItemProperty -Path "$UninstallPath\$ProdID" -ea SilentlyContinue |
        Select-Object -Property DisplayName, InstallDate, @{n='ProdID'; e={$ProdID}}, Publisher, DisplayVersion
} | Select-Object -First 3

For the sake of brevity, this example uses Select-Object to limit the number of items returned to three.

DisplayName    : 7-Zip 22.01 (x64)
InstallDate    :
ProdID         : 7-Zip
Publisher      : Igor Pavlov
DisplayVersion : 22.01

DisplayName    : AutoHotkey 1.1.33.10
InstallDate    :
ProdID         : AutoHotkey
Publisher      : Lexikos
DisplayVersion : 1.1.33.10

DisplayName    : Beyond Compare 4.4.6
InstallDate    : 20230310
ProdID         : BeyondCompare4_is1
Publisher      : Scooter Software
DisplayVersion : 4.4.6.27483