Implement root install loop using a switch

scripts/Windows/OS/Install.ps1

@@ -36,9 +36,12 @@ $null = New-Module {
     #>
     function Start-InstallationLoop {
         while (-not (Get-IsFinished)) {
-            if ($null -eq (Get-Stage)) {
+            switch (Get-Stage) {
+                ($null) {
                     Set-Stage ([SetupStage]::Initialize);
-            } elseif ((Get-Stage) -eq ([SetupStage]::Initialize)) {
+                    break;
+                }
+                ([SetupStage]::Initialize) {
                     if (-not ((Test-Command "choco") -and (Test-Command "refreshenv"))) {
                         Invoke-Hook "Install-Chocolatey" -Fallback {
                             # Install chocolatey
@@ -117,7 +120,9 @@ $null = New-Module {
                     };
 
                     Set-Stage ([SetupStage]::Configure);
-            } else {
+                    break;
+                }
+                default {
                     $null = Import-Module PSWindowsUpdate;
 
                     Invoke-Hook "Invoke-WindowsUpdate" -Fallback {
@@ -481,6 +486,7 @@ $null = New-Module {
                 }
             }
         }
+    }
 
     function Invoke-WindowsInstallation([Context] $context) {
         $Global:InformationPreference = "Continue";