Query registry for installed software

Question

Hoping someone can help me out with the two aspects of my script that I think is causing the most performance hindrance. Recreating the Array $Result and using the Get-ItemProperty on each and every key to get the required information. Is there a better way to accomplish this task?

Function Get-SoftwareList {
 <#
 #>
 Param()
 New-Variable -Force -ErrorAction SilentlyContinue -Name Result -Value @()
 New-Variable -Force -ErrorAction SilentlyContinue -Name Function -Value @{}
 $Function.Exclusions = (
 "Security Update for Windows",
 "Security Update for Microsoft",
 "Update for Windows",
 "Update for Microsoft",
 "Hotfix for Windows",
 "Update for Skype",
 "Security Update for Skype"
 )
 If([IntPtr]::Size -eq 8){ 
 $Function.OSArch='64-bit' 
 } Else{ 
 $Function.OSArch='32-bit' 
 }
 $Function.Registry = Get-Childitem -Path "HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall"
 IF ($Function.OSArch -EQ "64-bit") {
 $Function.Registry += Get-ChildItem -Path "HKLM:\Software\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall"
 }
 ForEach ($Key in $Function.Registry) {
 $Key = Get-ItemProperty -Path Registry::$Key
 IF ($Key.DisplayName.length -NE 0) {
 ForEach ($Exclusion in $Function.Exclusions) {
 If ($Key.DisplayName.StartsWith($Exclusion) -EQ $True) { 
 $Skip = $True
 Break
 } Else {
 $Skip = $False
 }
 }
 IF ($Skip -EQ $False) {
 $Result += New-Object PSObject -Property @{ 
 DisplayName = $Key.DisplayName
 Version = $Key.DisplayVersion 
 UninstallString = $Key.UninstallString
 Publisher = $Key.Publisher
 #ModifyPath = $Key.ModifyPath
 InstallDate = $Key.InstallDate
 }
 }
 }
 }
 Return $Result
}

Answer 1

Finding a very quick/reliable solution was actually significantly harder than I was expecting but this is the best I can come up with. It lists about ~130 applications in about 22ms on my computer.

 Function Get-InstalledSoftware {
 Param (
 [Array]$Properties = @('DisplayName','DisplayVersion')
 )
 $Keys = "Software\Microsoft\Windows\CurrentVersion\Uninstall","SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall"
 $Result = New-Object -TypeName 'System.Collections.ArrayList'
 $BaseKey = [Microsoft.Win32.RegistryKey]::OpenRemoteBaseKey([Microsoft.Win32.RegistryHive]::LocalMachine,$ENV:ComputerName)
 ForEach($Key in $Keys) {
 $RegKey = $BaseKey.OpenSubkey($key)
 If($RegKey -ne $null) {
 ForEach($subName in $RegKey.getsubkeynames()) {
 foreach($sub in $RegKey.opensubkey($subName)) {
 [string]$Name = $sub.getvalue("displayname")
 If ($Name.trim().Length -gt 0) {
 $HashProperty = @{}
 ForEach ($CurrentProperty in $Properties) {
 $HashProperty.$CurrentProperty = $sub.GetValue($CurrentProperty)
 }#End-ForEach
 $Result.add([psCustomObject]$HashProperty)
 }#End-IF
 }#End-ForEach
 }#End-Foreach
 }#End-IF
 }#End-ForEach
 $Result
}

The new script is not only significantly more flexible, but also significantly faster than previous solutions.

Measure-Command {
 for($i = 0; $i -lt 100; $i++) {
 Get-InstalledSoftware99 -Properties DisplayName,UninstallString,DisplayVersion
 }
}
Measure-Command {
 for($i = 0; $i -lt 100; $i++) {
 Get-SoftwareList
 }
}
Days : 0
Hours : 0
Minutes : 0
Seconds : 0
Milliseconds : 925
Ticks : 9259570
TotalDays : 1.07170949074074E-05
TotalHours : 0.000257210277777778
TotalMinutes : 0.0154326166666667
TotalSeconds : 0.925957
TotalMilliseconds : 925.957
Days : 0
Hours : 0
Minutes : 0
Seconds : 14
Milliseconds : 695
Ticks : 146959970
TotalDays : 0.00017009255787037
TotalHours : 0.00408222138888889
TotalMinutes : 0.244933283333333
TotalSeconds : 14.695997
TotalMilliseconds : 14695.997