Only install PowerShell module if necessary

scripts/Common/Scripts/SoftwareManagement.ps1

@@ -103,3 +103,18 @@ function Test-PSPackage {
 
     [bool] (Get-Package $Name -ErrorAction SilentlyContinue);
 }
+
+<#
+    .SYNOPSIS
+    Checks whether a module with the specified name is installed.
+
+    .PARAMETER Name
+    The name of the module to check.
+#>
+function Test-PSModule {
+    param(
+        [string] $Name
+    )
+
+    [bool](Get-Module -ListAvailable $Name -ErrorAction SilentlyContinue);
+}

scripts/Windows/OS/Install.ps1

@@ -179,9 +179,11 @@ $null = New-Module {
                                 };
                             }
 
-                            Install-Module -Scope AllUsers -AcceptLicense -Force $module[0] @parameters;
+                            if (-not (Test-PSModule $module[0])) {
+                                Install-Module -Scope AllUsers -AcceptLicense -Force -AllowClobber $module[0] @parameters;
                                 Import-Module $module[0];
                             }
+                        }
 
                         . "$PSScriptRoot/../Software/PinnedItem/Manage.ps1";
                     };