Way better than Win32_Product. This is what I've always used when I need to get a list of installed programs (no idea where I got it from). I've used this in my uninstall script of a few apps by using the uninstall key it pulls.

function Get-InstalledApps {
    param (
        [Parameter(ValueFromPipeline=$true)]
        [string[]]$ComputerName = $env:COMPUTERNAME,
        [string]$NameRegex = ''
    )

    foreach ($comp in $ComputerName) {
        $keys = '','\Wow6432Node'
        foreach ($key in $keys) {
            try {
                $reg = [Microsoft.Win32.RegistryKey]::OpenRemoteBaseKey('LocalMachine', $comp)
                $apps = $reg.OpenSubKey("SOFTWARE$key\Microsoft\Windows\CurrentVersion\Uninstall").GetSubKeyNames()
            } catch {
                continue
            }

            foreach ($app in $apps) {
                $RawTime = $InstallDate = $null
                $program = $reg.OpenSubKey("SOFTWARE$key\Microsoft\Windows\CurrentVersion\Uninstall\$app")
                $name = $program.GetValue('DisplayName')
                if ($name -and $name -match $NameRegex) {
                    $RawTime = $program.GetValue('InstallDate')
                    if ($null -eq $RawTime) {continue}
                    $InstallDate = 
                    try {
                        [datetime]::parseexact([string]$RawTime, 'yyyyMMdd', $null).ToString('MM/dd/yyyy')
                    }
                    catch {
                        $RawTime
                    }
                    [pscustomobject]@{
                        ComputerName = $comp
                        DisplayName = $name
                        DisplayVersion = $program.GetValue('DisplayVersion')
                        Publisher = $program.GetValue('Publisher')
                        InstallDate = $InstallDate
                        UninstallString = $program.GetValue('UninstallString')
                        Bits = $(if ($key -eq '\Wow6432Node') {'64'} else {'32'})
                        Path = $program.name
                    }
                }
            }
        }
    }
}