WMI not return all install programs on Windows 7 64

Question

Today we try to list all installed programs on each VM with following script to query WMI.

We find out it will list out all 64 bit applications, plus some of 32 bit applications.
But not all applications (32bit + 64bit) will list out.

param(
    [string] $ExportPath = ''
)

$InstalledProducts = get-wmiobject -class Win32_Product

if (($InstalledProducts -ne $null) -and ($InstalledProducts.Count -gt 0))
{
    $fileName = ($env:COMPUTERNAME) + "-" +  (Get-Date -f "yyyy-mm-dd-hhmmss") +  ".csv"
    $fileExport = $fileName
    if(Test-Path $ExportPath) {
        $fileExport = Join-Path (Resolve-Path $ExportPath) $fileName
    }
    $InstalledProducts | 
        Select-Object @{Name="HostName"; Expression={"$env:COMPUTERNAME"}}, Name, Version, Vendor | 
        Export-CSV -Path $fileExport -Encoding UTF8
}
else
{
    Write-Host "!!!ERROR!!!"
}

We also try "wmic product" it has the similar issue.
https://superuser.com/questions/681564/how-to-list-all-applications-displayed-from-add-remove-winxp-win7-via-command-li

Answer 1

At last, we need to merge all items both in

HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall

HKLM:\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall

Code:

param (
    [String] $ExportPath = '<NetworkPath>'
)

$fileName = ($ENV:COMPUTERNAME) + "-" + (Get-Date -f "yyyy-mm-dd-HHmmss") + ".csv"
$fileExport = $fileName

if (Test-Path $ExportPath) {
    $fileExport = Join-Path (Resolve-Path $ExportPath) $fileName
}

$UninstallRegList = ('HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall\*',
    'HKLM:\Software\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall\*')

$UninstallRegList |
    Get-ItemProperty |
    foreach{
        if (($_.DisplayName -ne $NULL) -and ($_.DisplayName -ne "")){
            $_
        }
    } | Select-Object DisplayName, DisplayVersion, Publisher |
    Export-CSV -Path $fileExport -Encoding UTF8

Here post explains that

The Win32_InstalledSoftwareElement and Win32_Product will only give you information about software that is installed by Microsoft Installer.

ref: WMI "installed" query different from add/remove programs list?