diff --git a/build/kvm.ps1 b/build/kvm.ps1
index 3e2acb9134..dc3d21cdd4 100644
--- a/build/kvm.ps1
+++ b/build/kvm.ps1
@@ -3,6 +3,7 @@ param(
   [string] $command,
   [switch] $verbosity = $false,
   [alias("g")][switch] $global = $false,
+  [alias("p")][switch] $persistent = $false,
   [switch] $x86 = $false,
   [switch] $x64 = $false,
   [switch] $svr50 = $false,
@@ -12,27 +13,37 @@ param(
 )
 
 $userKrePath = $env:USERPROFILE + "\.kre"
+$userKrePackages = $userKrePath + "\packages"
 $globalKrePath = $env:ProgramFiles + "\KRE"
+$globalKrePackages = $globalKrePath + "\packages"
 
 $scriptPath = $myInvocation.MyCommand.Definition
 
 function Kvm-Help {
 @"
-kvm - K Runtime Environment Version Manager
+K Runtime Environment Version Manager - Build {{BUILD_NUMBER}}
 
-kvm upgrade
+USAGE: kvm <command> [options]
+
+kvm upgrade [-x86][-x64] [-svr50][-svrc50] [-g|-global]
   install latest KRE from feed
-  set 'default' alias
-  add KRE bin to path of current command line
+  set 'default' alias to installed version
+  add KRE bin to user PATH environment variable persistently
+  -g|-global        install to machine-wide location
 
-kvm install <semver>|<alias> [-x86][-x64] [-svr50][-svrc50] [-g|-global]
+kvm install <semver>|<alias>|<nupkg> [-x86][-x64] [-svr50][-svrc50] [-g|-global]
   install requested KRE from feed
-
-kvm list [-g|-global]
-  list KRE versions installed 
-
-kvm use <semver>|<alias> [-x86][-x64] [-svr50][-svrc50] [-g|-global]
   add KRE bin to path of current command line
+  -g|-global        install to machine-wide location
+
+kvm use <semver>|<alias>|none [-x86][-x64] [-svr50][-svrc50] [-p|-persistent] [-g|-global]
+  <semver>|<alias>  add KRE bin to path of current command line   
+  none              remove KRE bin from path of current command line
+  -p|-persistent    add KRE bin to PATH environment variables persistently
+  -g|-global        combined with -p to change machine PATH instead of user PATH
+
+kvm list
+  list KRE versions installed 
 
 kvm alias
   list KRE aliases which have been defined
@@ -46,14 +57,70 @@ kvm alias <alias> <semver> [-x86][-x64] [-svr50][-svrc50]
 "@ | Write-Host
 }
 
+function Kvm-Global-Setup {
+    If (Needs-Elevation)
+    {
+        $arguments = "& '$scriptPath' setup $(Requested-Switches) -persistent"
+        Start-Process "$psHome\powershell.exe" -Verb runAs -ArgumentList $arguments -Wait
+        Write-Host "Setup complete"
+        Kvm-Help
+        break
+    }
+
+    $scriptFolder = [System.IO.Path]::GetDirectoryName($scriptPath)
+
+    $kvmBinPath = "$userKrePath\bin"
+
+    Write-Host "Copying file $kvmBinPath\kvm.ps1"
+    md $kvmBinPath -Force | Out-Null
+    copy "$scriptFolder\kvm.ps1" "$kvmBinPath\kvm.ps1"
+
+    Write-Host "Copying file $kvmBinPath\kvm.cmd"
+    copy "$scriptFolder\kvm.cmd" "$kvmBinPath\kvm.cmd"
+
+    Write-Host "Adding $kvmBinPath to process PATH"
+    Set-Path (Change-Path $env:Path $kvmBinPath ($kvmBinPath))
+
+    Write-Host "Adding $kvmBinPath to user PATH"
+    $userPath = [Environment]::GetEnvironmentVariable("Path", [System.EnvironmentVariableTarget]::User)
+    $userPath = Change-Path $userPath $kvmBinPath ($kvmBinPath)
+    [Environment]::SetEnvironmentVariable("Path", $userPath, [System.EnvironmentVariableTarget]::User)
+
+    Write-Host "Adding $globalKrePath;%USERPROFILE%\.kre to process KRE_HOME"
+    $envKreHome = $env:KRE_HOME
+    $envKreHome = Change-Path $envKreHome "%USERPROFILE%\.kre" ("%USERPROFILE%\.kre")
+    $envKreHome = Change-Path $envKreHome $globalKrePath ($globalKrePath)
+    $env:KRE_HOME = $envKreHome
+
+    Write-Host "Adding $globalKrePath;%USERPROFILE%\.kre to machine KRE_HOME"
+    $machineKreHome = [Environment]::GetEnvironmentVariable("KRE_HOME", [System.EnvironmentVariableTarget]::Machine)
+    $machineKreHome = Change-Path $machineKreHome "%USERPROFILE%\.kre" ("%USERPROFILE%\.kre")
+    $machineKreHome = Change-Path $machineKreHome $globalKrePath ($globalKrePath)
+    [Environment]::SetEnvironmentVariable("KRE_HOME", $machineKreHome, [System.EnvironmentVariableTarget]::Machine)
+
+    Write-Host "Press any key to continue ..."
+    $x = $host.UI.RawUI.ReadKey("NoEcho,IncludeKeyDown,AllowCtrlC")
+}
+
+function Kvm-Global-Upgrade {
+    $persistent = $true
+    If (Needs-Elevation) {
+        $arguments = "& '$scriptPath' upgrade -global $(Requested-Switches)"
+        Start-Process "$psHome\powershell.exe" -Verb runAs -ArgumentList $arguments -Wait
+        break
+    }
+    $version = Kvm-Find-Latest (Requested-Platform "svr50") (Requested-Architecture "x86")
+    Kvm-Global-Install $version
+    Kvm-Alias-Set "default" $version
+}
 
 function Kvm-Upgrade {
+    $persistent = $true
     $version = Kvm-Find-Latest (Requested-Platform "svr50") (Requested-Architecture "x86")
     Kvm-Install $version
     Kvm-Alias-Set "default" $version
 }
 
-
 function Kvm-Find-Latest {
 param(
     [string] $platform,
@@ -87,7 +154,8 @@ param(
     $kreFile = "$kreFolder\$kreFullName.nupkg"
 
     If (Test-Path $kreFolder) {
-        Remove-Item $kreFolder -Force -Recurse
+      Write-Host "$kreFullName already installed."
+      return;
     }
 
     Write-Host "Downloading" $kreFullName "from https://www.myget.org/F/aspnetvnext/api/v2/"
@@ -122,6 +190,23 @@ param(
     }
 }
 
+function Kvm-Global-Install {
+param(
+  [string] $versionOrAlias
+)
+    If (Needs-Elevation) {
+        $arguments = "& '$scriptPath' install -global $versionOrAlias $(Requested-Switches)"
+        Start-Process "$psHome\powershell.exe" -Verb runAs -ArgumentList $arguments -Wait
+        Kvm-Global-Use $versionOrAlias
+        break
+    }
+
+    $kreFullName = Requested-VersionOrAlias $versionOrAlias
+    $kreFolder = "$globalKrePackages\$kreFullName"
+    Do-Kvm-Download $kreFullName $kreFolder
+    Kvm-Use $versionOrAlias
+}
+
 function Kvm-Install {
 param(
   [string] $versionOrAlias
@@ -129,103 +214,148 @@ param(
     if ($versionOrAlias.EndsWith(".nupkg"))
     {
         $kreFullName = [System.IO.Path]::GetFileNameWithoutExtension($versionOrAlias)
-        $kreFolder = "$userKrePath\packages\$kreFullName"
+        $kreFolder = "$userKrePackages\$kreFullName"
         $kreFile = "$kreFolder\$kreFullName.nupkg"
 
-        md $kreFolder -Force | Out-Null
+        if (Test-Path($kreFolder)) {
+          Write-Host "Target folder '$kreFolder' already exists"
+        } else {
+          md $kreFolder -Force | Out-Null
+          copy $versionOrAlias $kreFile
+          Do-Kvm-Unpack $kreFile $kreFolder
+        }
 
-        copy $versionOrAlias $kreFile
-
-        Do-Kvm-Unpack $kreFile $kreFolder
+        $kreBin = "$kreFolder\bin"
+        Write-Host "Adding" $kreBin "to process PATH"
+        Set-Path (Change-Path $env:Path $kreBin ($globalKrePackages, $userKrePackages))
     }
     else
     {
         $kreFullName = Requested-VersionOrAlias $versionOrAlias
 
-        $kreFolder = "$userKrePath\packages\$kreFullName"
+        $kreFolder = "$userKrePackages\$kreFullName"
 
         Do-Kvm-Download $kreFullName $kreFolder
         Kvm-Use $versionOrAlias
     }
 }
 
-function Kvm-Global-Install {
-param(
-  [string] $versionOrAlias
-)
-    If (-NOT ([Security.Principal.WindowsPrincipal][Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole] "Administrator"))
-    {
-        $arguments = "install -global $versionOrAlias" 
-        if ($x86) {$arguments = "$arguments -x86"}
-        if ($x64) {$arguments = "$arguments -x64"}
-        if ($svr50) {$arguments = "$arguments -svr50"}
-        if ($svrc50) {$arguments = "$arguments -svrc50"}
-
-        $arguments = "& '$scriptPath' $arguments"
-        Start-Process "$psHome\powershell.exe" -Verb runAs -ArgumentList $arguments
-        Kvm-Global-Use $versionOrAlias
-        break
-    }
-
-    $kreFullName = Requested-VersionOrAlias $versionOrAlias
-
-    $kreFolder = $globalKrePath + "\packages\$kreFullName"
-
-    Do-Kvm-Download $kreFullName $kreFolder
-}
-
 function Kvm-List {
-    Get-ChildItem ($userKrePath + "\packages\") | Select Name
-}
-
-function Kvm-Global-List {
-    Get-ChildItem ($globalKrePath + "\packages\") | Select Name
-}
-
-function Kvm-Use {
-param(
-  [string] $versionOrAlias
-)
-    $kreFullName = Requested-VersionOrAlias $versionOrAlias
-
-    $kreBin = $userKrePath + "\packages\" + $kreFullName + "\bin"
-
-    Write-Host "Adding" $kreBin "to PATH"
-
-    $newPath = $kreBin
-    foreach($portion in $env:Path.Split(';')) {
-      if (!$portion.StartsWith($userKrePath) -and !$portion.StartsWith($globalKrePath)) {
-        $newPath = $newPath + ";" + $portion
-      }
+  $kreHome = $env:KRE_HOME
+  if (!$kreHome) {
+    $kreHome = $env:ProgramFiles + "\KRE;%USERPROFILE%\.kre"
+  }
+  $items = @()
+  foreach($portion in $kreHome.Split(';')) {
+    $path = [System.Environment]::ExpandEnvironmentVariables($portion)
+    if (Test-Path("$path\packages")) {
+      $items += Get-ChildItem ("$path\packages\KRE-*") | List-Parts
     }
+  }
+  $items | Sort-Object Version, Runtime, Architecture | Format-Table -AutoSize -Property @{name="Active";expression={$_.Active};alignment="center"}, "Version", "Runtime", "Architecture", "Location"
+}
 
-@"
-SET "KRE_VERSION=$version"
-SET "PATH=$newPath"
-"@ | Out-File ($userKrePath + "\run-once.cmd") ascii
+filter List-Parts {
+  $hasBin = Test-Path($_.FullName+"\bin") 
+  if (!$hasBin) {
+    return
+  }
+  $active = $false
+  foreach($portion in $env:Path.Split(';')) {
+    if ($portion.StartsWith($_.FullName)) {
+      $active = $true
+    }
+  }
+  $parts1 = $_.Name.Split('.', 2)
+  $parts2 = $parts1[0].Split('-', 3)
+  return New-Object PSObject -Property @{
+    Active = if($active){"*"}else{""}
+    Version = $parts1[1]
+    Runtime = $parts2[1]
+    Architecture = $parts2[2]
+    Location = $_.Parent.FullName
+  }
 }
 
 function Kvm-Global-Use {
 param(
   [string] $versionOrAlias
 )
-    $kreFullName = Requested-VersionOrAlias $versionOrAlias
-
-    $kreBin = "$globalKrePath\packages\$kreFullName\bin"
-
-    Write-Host "Adding" $kreBin "to PATH"
-
-    $newPath = $kreBin
-    foreach($portion in $env:Path.Split(';')) {
-      if (!$portion.StartsWith($userKrePath) -and !$portion.StartsWith($globalKrePath)) {
-        $newPath = $newPath + ";" + $portion
-      }
+    If (Needs-Elevation) {
+        $arguments = "& '$scriptPath' use -global $versionOrAlias $(Requested-Switches)"
+        if ($persistent) {
+          $arguments = $arguments + " -persistent"
+        }
+        Start-Process "$psHome\powershell.exe" -Verb runAs -ArgumentList $arguments -Wait
+        break
     }
 
-@"
-SET "KRE_VERSION=$version"
-SET "PATH=$newPath"
-"@ | Out-File ($userKrePath + "\run-once.cmd") ascii
+    if ($versionOrAlias -eq "none") {
+      Write-Host "Removing KRE from process PATH"
+      Set-Path (Change-Path $env:Path "" ($globalKrePackages, $userKrePackages))
+
+      if ($persistent) {  
+          Write-Host "Removing KRE from machine PATH"
+          $machinePath = [Environment]::GetEnvironmentVariable("Path", [System.EnvironmentVariableTarget]::Machine)
+          $machinePath = Change-Path $machinePath "" ($globalKrePackages, $userKrePackages)
+          [Environment]::SetEnvironmentVariable("Path", $machinePath, [System.EnvironmentVariableTarget]::Machine)
+      }
+      return;
+    }
+
+    $kreFullName = Requested-VersionOrAlias $versionOrAlias
+
+    $kreBin = Locate-KreBinFromFullName $kreFullName
+    if ($kreBin -eq $null) {
+      Write-Host "Cannot find $kreFullName, do you need to run 'kvm install $versionOrAlias'?"
+      return
+    } 
+
+    Write-Host "Adding" $kreBin "to process PATH"
+    Set-Path (Change-Path $env:Path $kreBin ($globalKrePackages, $userKrePackages))
+
+    if ($persistent) {
+        Write-Host "Adding $kreBin to machine PATH"
+        $machinePath = [Environment]::GetEnvironmentVariable("Path", [System.EnvironmentVariableTarget]::Machine)
+        $machinePath = Change-Path $machinePath $kreBin ($globalKrePackages, $userKrePackages)
+        [Environment]::SetEnvironmentVariable("Path", $machinePath, [System.EnvironmentVariableTarget]::Machine)
+    }
+}
+
+function Kvm-Use {
+param(
+  [string] $versionOrAlias
+)
+    if ($versionOrAlias -eq "none") {
+      Write-Host "Removing KRE from process PATH"
+      Set-Path (Change-Path $env:Path "" ($globalKrePackages, $userKrePackages))
+
+      if ($persistent) {  
+          Write-Host "Removing KRE from user PATH"
+          $userPath = [Environment]::GetEnvironmentVariable("Path", [System.EnvironmentVariableTarget]::User)
+          $userPath = Change-Path $userPath "" ($globalKrePackages, $userKrePackages)
+          [Environment]::SetEnvironmentVariable("Path", $userPath, [System.EnvironmentVariableTarget]::User)
+      }
+      return;
+    }
+
+    $kreFullName = Requested-VersionOrAlias $versionOrAlias
+
+    $kreBin = Locate-KreBinFromFullName $kreFullName
+    if ($kreBin -eq $null) {
+      Write-Host "Cannot find $kreFullName, do you need to run 'kvm install $versionOrAlias'?"
+      return
+    } 
+
+    Write-Host "Adding" $kreBin "to process PATH"
+    Set-Path (Change-Path $env:Path $kreBin ($globalKrePackages, $userKrePackages))
+
+    if ($persistent) {  
+        Write-Host "Adding $kreBin to user PATH"
+        $userPath = [Environment]::GetEnvironmentVariable("Path", [System.EnvironmentVariableTarget]::User)
+        $userPath = Change-Path $userPath $kreBin ($globalKrePackages, $userKrePackages)
+        [Environment]::SetEnvironmentVariable("Path", $userPath, [System.EnvironmentVariableTarget]::User)
+    }
 }
 
 function Kvm-Alias-List {
@@ -254,6 +384,24 @@ param(
     $kreFullName | Out-File ($userKrePath + "\alias\" + $name + ".txt") ascii
 }
 
+function Locate-KreBinFromFullName() {
+param(
+  [string] $kreFullName
+)
+  $kreHome = $env:KRE_HOME
+  if (!$kreHome) {
+    $kreHome = $env:ProgramFiles + ";%USERPROFILE%\.kre"
+  }
+  foreach($portion in $kreHome.Split(';')) {
+    $path = [System.Environment]::ExpandEnvironmentVariables($portion)
+    $kreBin = "$path\packages\$kreFullName\bin"
+    if (Test-Path "$kreBin") {
+      return $kreBin
+    }
+  }
+  return $null
+}
+
 function Requested-VersionOrAlias() {
 param(
   [string] $versionOrAlias
@@ -305,28 +453,77 @@ param(
     return $default
 }
 
+function Change-Path() {
+param(
+  [string] $existingPaths,
+  [string] $prependPath,
+  [string[]] $removePaths
+)
+    $newPath = $prependPath
+    foreach($portion in $existingPaths.Split(';')) {
+      $skip = $portion -eq ""
+      foreach($removePath in $removePaths) {
+        if ($portion.StartsWith($removePath)) {
+          $skip = $true
+        }      
+      }
+      if (!$skip) {
+        $newPath = $newPath + ";" + $portion
+      }
+    }
+    return $newPath
+}
+
+function Set-Path() {
+param(
+  [string] $newPath
+)
+  md $userKrePath -Force | Out-Null
+  $env:Path = $newPath
+@"
+SET "PATH=$newPath"
+"@ | Out-File ($userKrePath + "\run-once.cmd") ascii
+}
+
+function Needs-Elevation() {
+    $user = [Security.Principal.WindowsPrincipal][Security.Principal.WindowsIdentity]::GetCurrent()
+    $elevated = $user.IsInRole([Security.Principal.WindowsBuiltInRole] "Administrator")
+    return -NOT $elevated
+}
+
+function Requested-Switches() {
+  $arguments = ""
+  if ($x86) {$arguments = "$arguments -x86"}
+  if ($x64) {$arguments = "$arguments -x64"}
+  if ($svr50) {$arguments = "$arguments -svr50"}
+  if ($svrc50) {$arguments = "$arguments -svrc50"}
+  return $arguments
+}
 
  try {
    if ($global) {
     switch -wildcard ($command + " " + $args.Count) {
-#      "upgrade 0"         {Kvm-Global-Upgrade}
+      "setup 0"           {Kvm-Global-Setup}
+      "upgrade 0"         {Kvm-Global-Upgrade}
 #      "install 0"         {Kvm-Global-Install-Latest}
       "install 1"         {Kvm-Global-Install $args[0]}
-      "list 0"            {Kvm-Global-List}
+#      "list 0"            {Kvm-Global-List}
       "use 1"             {Kvm-Global-Use $args[0]}
       default             {Write-Host 'Unknown command, or global switch not supported'; Kvm-Help;}
     }
    } else {
     switch -wildcard ($command + " " + $args.Count) {
+      "setup 0"           {Kvm-Global-Setup}
       "upgrade 0"         {Kvm-Upgrade}
-      "install 0"         {Kvm-Install-Latest}
+#      "install 0"         {Kvm-Install-Latest}
       "install 1"         {Kvm-Install $args[0]}
       "list 0"            {Kvm-List}
       "use 1"             {Kvm-Use $args[0]}
       "alias 0"           {Kvm-Alias-List}
       "alias 1"           {Kvm-Alias-Get $args[0]}
       "alias 2"           {Kvm-Alias-Set $args[0] $args[1]}
-      "help"              {Kvm-Help}
+      "help 0"              {Kvm-Help}
+      " 0"              {Kvm-Help}
       default             {Write-Host 'Unknown command'; Kvm-Help;}
     }
    }