Get-InstalledSoftware.ps1

Function Get-InstalledSoftware {
    <#
    .SYNOPSIS
        Get-InstalledSoftware retrieves a list of installed software
    .DESCRIPTION
        Get-InstalledSoftware opens up the specified (remote) registry and scours it for installed software. When found it returns a list of the software and it's version.
    .PARAMETER ComputerName
        The computer from which you want to get a list of installed software. Defaults to the local host.
    .EXAMPLE
        Get-InstalledSoftware DC1
        
        This will return a list of software from DC1. Like:
        Name			Version		Computer  UninstallCommand
        ----			-------     --------  ----------------
        7-Zip 			9.20.00.0	DC1       MsiExec.exe /I{23170F69-40C1-2702-0920-000001000000}
        Google Chrome	65.119.95	DC1       MsiExec.exe /X{6B50D4E7-A873-3102-A1F9-CD5B17976208}
        Opera			12.16		DC1		  "C:\Program Files (x86)\Opera\Opera.exe" /uninstall
    .EXAMPLE
        Import-Module ActiveDirectory
        Get-ADComputer -filter 'name -like "DC*"' | Get-InstalledSoftware
        
        This will get a list of installed software on every AD computer that matches the AD filter (So all computers with names starting with DC)
    .INPUTS
        [string[]]Computername
    .OUTPUTS
        PSObject with properties: Name,Version,Computer,UninstallCommand
    .NOTES
        Copied from: https://community.spiceworks.com/scripts/show_download/2170-get-a-list-of-installed-software-from-a-remote-computer-fast-as-lightning

        Author: Anthony Howell
        
        To add directories, add to the LMkeys (LocalMachine)    
    .LINK
        [Microsoft.Win32.RegistryHive]
        [Microsoft.Win32.RegistryKey]
    #>

    Param(
        [Alias('Computer','ComputerName','HostName')]
        [Parameter(
            ValueFromPipeline=$True,
            ValueFromPipelineByPropertyName=$true,
            Position=1
        )]
        [string]$Name = $env:COMPUTERNAME
    )
    
    Begin{
        $lmKeys = "Software\Microsoft\Windows\CurrentVersion\Uninstall","SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall"
        $lmReg = [Microsoft.Win32.RegistryHive]::LocalMachine
        $cuKeys = "Software\Microsoft\Windows\CurrentVersion\Uninstall"
        $cuReg = [Microsoft.Win32.RegistryHive]::CurrentUser
    }
    Process{
        if ( ($Name -ne $env:COMPUTERNAME) -and ( -not (Test-Connection -ComputerName $Name -count 1 -quiet))) {
            Write-Error -Message "Unable to contact $Name. Please verify its network connectivity and try again." -Category ObjectNotFound -TargetObject $Computer
            Break
        }
        $masterKeys = @()
        $remoteCURegKey = [Microsoft.Win32.RegistryKey]::OpenRemoteBaseKey($cuReg,$computer)
        $remoteLMRegKey = [Microsoft.Win32.RegistryKey]::OpenRemoteBaseKey($lmReg,$computer)
        foreach ($key in $lmKeys) {
            $regKey = $remoteLMRegKey.OpenSubkey($key)
            foreach ($subName in $regKey.GetSubkeyNames()) {
                foreach($sub in $regKey.OpenSubkey($subName)) {
                    $masterKeys += (New-Object PSObject -Property @{
                        "ComputerName" = $Name
                        "Name" = $sub.getvalue("displayname")
                        "SystemComponent" = $sub.getvalue("systemcomponent")
                        "ParentKeyName" = $sub.getvalue("parentkeyname")
                        "Version" = $sub.getvalue("DisplayVersion")
                        "UninstallCommand" = $sub.getvalue("UninstallString")
                        "InstallDate" = $sub.getvalue("InstallDate")
                        "RegPath" = $sub.ToString()
                    })
                }
            }
        }
        foreach ($key in $cuKeys) {
            $regKey = $remoteCURegKey.OpenSubkey($key)
            if ($regKey -ne $null) {
                foreach ($subName in $regKey.getsubkeynames()) {
                    foreach ($sub in $regKey.opensubkey($subName)) {
                        $masterKeys += (New-Object PSObject -Property @{
                            "ComputerName" = $Name
                            "Name" = $sub.getvalue("displayname")
                            "SystemComponent" = $sub.getvalue("systemcomponent")
                            "ParentKeyName" = $sub.getvalue("parentkeyname")
                            "Version" = $sub.getvalue("DisplayVersion")
                            "UninstallCommand" = $sub.getvalue("UninstallString")
                            "InstallDate" = $sub.getvalue("InstallDate")
                            "RegPath" = $sub.ToString()
                        })
                    }
                }
            }
        }
        $woFilter = {$null -ne $_.name -AND $_.SystemComponent -ne "1" -AND $null -eq $_.ParentKeyName}
        $props = 'Name','Version','ComputerName','Installdate','UninstallCommand','RegPath'
        $masterKeys = ($masterKeys | Where-Object $woFilter | Select-Object $props | Sort-Object Name)
        $masterKeys
    }
    End{}
}