PowerShell · bmanikm · Sep 13, 2018 · Aug 22, 2018 · Aug 22, 2018 · Aug 24, 2018
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,4 +1,10 @@
 # Changelog
+## 2.0.0
+Breaking Change
+- Default installation scope for Install-Module, Install-Script, and Install-Package has changed. For Windows PowerShell (version 5.1 or below), the default scope is AllUsers when running in an elevated session, and CurrentUser at all other times.
+  For PowerShell version 6.0.0 and above, the default installation scope is always CurrentUser.
+
+
 ## 1.6.7
 
 Bug fixes

diff --git a/PowerShellGet/PSGet.Resource.psd1 b/PowerShellGet/PSGet.Resource.psd1
@@ -22,8 +22,8 @@ ConvertFrom-StringData @'
         RequiredVersionAllowedOnlyWithSingleModuleName=The RequiredVersion parameter is allowed only when a single module name is specified as the value of the Name parameter, without any wildcard characters.
         MinimumVersionIsGreaterThanMaximumVersion=The specified MinimumVersion '{0}' is greater than the specified MaximumVersion '{1}'.
         AllowPrereleaseRequiredToUsePrereleaseStringInVersion=The '-AllowPrerelease' parameter must be specified when using the Prerelease string in MinimumVersion, MaximumVersion, or RequiredVersion. 
-        InstallModuleNeedsCurrentUserScopeParameterForNonAdminUser=Administrator rights are required to install modules in '{0}'. Log on to the computer with an account that has Administrator rights, and then try again, or install '{1}' by adding "-Scope CurrentUser" to your command. You can also try running the Windows PowerShell session with elevated rights (Run as Administrator).
-        InstallScriptNeedsCurrentUserScopeParameterForNonAdminUser=Administrator rights are required to install scripts in '{0}'. Log on to the computer with an account that has Administrator rights, and then try again, or install '{1}' by adding "-Scope CurrentUser" to your command. You can also try running the Windows PowerShell session with elevated rights (Run as Administrator).
+        InstallModuleAdminPrivilegeRequiredForAllUsersScope=Administrator rights are required to install modules in '{0}'. Log on to the computer with an account that has Administrator rights, and then try again, or install '{1}' by adding "-Scope CurrentUser" to your command. You can also try running the Windows PowerShell session with elevated rights (Run as Administrator).
+        InstallScriptAdminPrivilegeRequiredForAllUsersScope=Administrator rights are required to install scripts in '{0}'. Log on to the computer with an account that has Administrator rights, and then try again, or install '{1}' by adding "-Scope CurrentUser" to your command. You can also try running the Windows PowerShell session with elevated rights (Run as Administrator).
         AdministratorRightsNeededOrSpecifyCurrentUserScope=Administrator rights are required to install or update. Log on to the computer with an account that has Administrator rights, and then try again, or install by adding "-Scope CurrentUser" to your command. You can also try running the Windows PowerShell session with elevated rights (Run as Administrator).
         VersionParametersAreAllowedOnlyWithSingleName=The RequiredVersion, MinimumVersion, MaximumVersion, AllVersions or AllowPrerelease parameters are allowed only when you specify a single name as the value of the Name parameter, without any wildcard characters.
         PathIsNotADirectory=The specified path '{0}' is not a valid directory.

diff --git a/PowerShellGet/PowerShellGet.psd1 b/PowerShellGet/PowerShellGet.psd1
@@ -1,6 +1,6 @@
 @{
 RootModule = 'PSModule.psm1'
-ModuleVersion = '1.6.7'
+ModuleVersion = '2.0.0'
 GUID = '1d73a601-4a6c-43c5-ba3f-619b18bbb404'
 Author = 'Microsoft Corporation'
 CompanyName = 'Microsoft Corporation'
@@ -54,6 +54,12 @@ PrivateData = @{
         ProjectUri = 'https://go.microsoft.com/fwlink/?LinkId=828955'
         LicenseUri = 'https://go.microsoft.com/fwlink/?LinkId=829061'
         ReleaseNotes = @'
+## 2.0.0
+
+Breaking Change
+- Default installation scope for Install-Module, Install-Script, and Install-Package has changed. For Windows PowerShell (version 5.1 or below), the default scope is AllUsers when running in an elevated session, and CurrentUser at all other times.
+  For PowerShell version 6.0.0 and above, the default installation scope is always CurrentUser.
+
 ## 1.6.7
 
 Bug fixes

diff --git a/PowerShellGet/private/functions/Install-PackageUtility.ps1 b/PowerShellGet/private/functions/Install-PackageUtility.ps1
@@ -64,13 +64,13 @@ function Install-PackageUtility
 
         if($artifactType -eq $script:PSArtifactTypeScript)
         {
-            $AdminPrivilegeErrorMessage = $LocalizedData.InstallScriptNeedsCurrentUserScopeParameterForNonAdminUser -f @($script:ProgramFilesScriptsPath, $script:MyDocumentsScriptsPath)
-            $AdminPrivilegeErrorId = 'InstallScriptNeedsCurrentUserScopeParameterForNonAdminUser'
+            $AdminPrivilegeErrorMessage = $LocalizedData.InstallScriptAdminPrivilegeRequiredForAllUsersScope -f @($script:ProgramFilesScriptsPath, $script:MyDocumentsScriptsPath)
+            $AdminPrivilegeErrorId = 'InstallScriptAdminPrivilegeRequiredForAllUsersScope'
         }
         else
         {
-            $AdminPrivilegeErrorMessage = $LocalizedData.InstallModuleNeedsCurrentUserScopeParameterForNonAdminUser -f @($script:programFilesModulesPath, $script:MyDocumentsModulesPath)
-            $AdminPrivilegeErrorId = 'InstallModuleNeedsCurrentUserScopeParameterForNonAdminUser'
+            $AdminPrivilegeErrorMessage = $LocalizedData.InstallModuleAdminPrivilegeRequiredForAllUsersScope -f @($script:programFilesModulesPath, $script:MyDocumentsModulesPath)
+            $AdminPrivilegeErrorId = 'InstallModuleAdminPrivilegeRequiredForAllUsersScope'
         }
 
         $installUpdate = $false
@@ -101,7 +101,7 @@ function Install-PackageUtility
 
                     if(-not (Test-RunningAsElevated))
                     {
-                        # Throw an error when Install-Module/Script is used as a non-admin user and '-Scope CurrentUser' is not specified
+                        # Throw an error when Install-Module/Script is used as a non-admin user and '-Scope AllUsers'
                         ThrowError -ExceptionName "System.ArgumentException" `
                                     -ExceptionMessage $AdminPrivilegeErrorMessage `
                                     -ErrorId $AdminPrivilegeErrorId `
@@ -118,14 +118,17 @@ function Install-PackageUtility
                 $moduleDestination = $Location
                 $scriptDestination = $Location
             }
-            # if no scope and no destination path and not elevated, then raise an error
-            elseif(-not (Test-RunningAsElevated))
+            elseif(-not $script:IsCoreCLR -and (Test-RunningAsElevated))
             {
-                ThrowError -ExceptionName "System.ArgumentException" `
-                           -ExceptionMessage $AdminPrivilegeErrorMessage `
-                           -ErrorId $AdminPrivilegeErrorId `
-                           -CallerPSCmdlet $PSCmdlet `
-                           -ErrorCategory InvalidArgument
+                # If Windows and elevated default scope will be all users
+                $scriptDestination = $script:ProgramFilesScriptsPath
+                $moduleDestination = $script:ProgramFilesModulesPath
+            }
+            else
+            {
+                # If non-Windows or non-elevated default scope will be current user
+                $scriptDestination = $script:MyDocumentsScriptsPath
+                $moduleDestination = $script:MyDocumentsModulesPath
             }
 
             if($options.ContainsKey('SkipPublisherCheck'))

diff --git a/PowerShellGet/public/psgetfunctions/Install-Module.ps1 b/PowerShellGet/public/psgetfunctions/Install-Module.ps1
@@ -55,7 +55,7 @@ function Install-Module
         [Parameter()]
         [ValidateSet("CurrentUser","AllUsers")]
         [string]
-        $Scope = "AllUsers",
+        $Scope,
 
         [Parameter(ValueFromPipelineByPropertyName=$true)]
         [ValidateNotNullOrEmpty()]
@@ -91,18 +91,29 @@ function Install-Module
     {
         Get-PSGalleryApiAvailability -Repository $Repository
 
-        if(-not (Test-RunningAsElevated) -and ($Scope -ne "CurrentUser"))
+        if($Scope -eq "AllUsers" -and -not (Test-RunningAsElevated))
         {
-            # Throw an error when Install-Module is used as a non-admin user and '-Scope CurrentUser' is not specified
-            $message = $LocalizedData.InstallModuleNeedsCurrentUserScopeParameterForNonAdminUser -f @($script:programFilesModulesPath, $script:MyDocumentsModulesPath)
+            # Throw an error when Install-Module is used as a non-admin user and '-Scope AllUsers'
+            $message = $LocalizedData.InstallModuleAdminPrivilegeRequiredForAllUsersScope -f @($script:programFilesModulesPath, $script:MyDocumentsModulesPath)
 
             ThrowError -ExceptionName "System.ArgumentException" `
                         -ExceptionMessage $message `
-                        -ErrorId "InstallModuleNeedsCurrentUserScopeParameterForNonAdminUser" `
+                        -ErrorId "InstallModuleAdminPrivilegeRequiredForAllUsersScope" `
                         -CallerPSCmdlet $PSCmdlet `
                         -ErrorCategory InvalidArgument
         }
 
+        # If no scope is specified, default installation will be to AllUsers only 
+        # If running admin on Windows with PowerShell less than v6.
+        if (-not $Scope) 
+        {
+            $Scope = "CurrentUser"
+            if(-not $script:IsCoreCLR -and (Test-RunningAsElevated))
+            {
+                $Scope = "AllUsers"
+            }
+        }
+
         Install-NuGetClientBinaries -CallerPSCmdlet $PSCmdlet -Proxy $Proxy -ProxyCredential $ProxyCredential
 
         # Module names already tried in the current pipeline for InputObject parameterset

diff --git a/PowerShellGet/public/psgetfunctions/Install-Script.ps1 b/PowerShellGet/public/psgetfunctions/Install-Script.ps1
@@ -51,7 +51,7 @@ function Install-Script
         [Parameter()]
         [ValidateSet("CurrentUser","AllUsers")]
         [string]
-        $Scope = 'AllUsers',
+        $Scope,
 
         [Parameter()]
         [Switch]
@@ -87,19 +87,29 @@ function Install-Script
     {
         Get-PSGalleryApiAvailability -Repository $Repository
 
-        if(-not (Test-RunningAsElevated) -and ($Scope -ne "CurrentUser"))
+        if($Scope -eq "AllUsers" -and -not (Test-RunningAsElevated))
         {
-            # Throw an error when Install-Script is used as a non-admin user and '-Scope CurrentUser' is not specified
-            $AdminPrivilegeErrorMessage = $LocalizedData.InstallScriptNeedsCurrentUserScopeParameterForNonAdminUser -f @($script:ProgramFilesScriptsPath, $script:MyDocumentsScriptsPath)
-            $AdminPrivilegeErrorId = 'InstallScriptNeedsCurrentUserScopeParameterForNonAdminUser'
+            # Throw an error when Install-Script is used as a non-admin user and '-Scope AllUsers'
+            $message = $LocalizedData.InstallScriptAdminPrivilegeRequiredForAllUsersScope -f @($script:ProgramFilesScriptsPath, $script:MyDocumentsScriptsPath)
 
             ThrowError -ExceptionName "System.ArgumentException" `
-                        -ExceptionMessage $AdminPrivilegeErrorMessage `
-                        -ErrorId $AdminPrivilegeErrorId `
+                        -ExceptionMessage $message `
+                        -ErrorId "InstallScriptAdminPrivilegeRequiredForAllUsersScope" `
                         -CallerPSCmdlet $PSCmdlet `
                         -ErrorCategory InvalidArgument
         }
 
+        # If no scope is specified, default installation will be to AllUsers only 
+        # If running admin on Windows with PowerShell less than v6.
+        if (-not $Scope) 
+        {
+            $Scope = "CurrentUser"
+            if(-not $script:IsCoreCLR -and (Test-RunningAsElevated))
+            {
+                $Scope = "AllUsers"
+            }
+        }
+
         # Check and add the scope path to PATH environment variable
         if($Scope -eq 'AllUsers')
         {