Powershell script to auto install of IIS 7 and above

With certain changes from using help we are able to install IIS from power shell with custom role services.I have the code here and the link to the blog is: http://www.ithassle.nl/2010/09/powershell-script-to-install-and-configure-iis7-5/#codesyntax_1

# --------------------------------------------------------------------
# Checking Execution Policy
# --------------------------------------------------------------------
#$Policy = "Unrestricted"
$Policy = "RemoteSigned"
If ((get-ExecutionPolicy) -ne $Policy) {
  Write-Host "Script Execution is disabled. Enabling it now"
  Set-ExecutionPolicy $Policy -Force
  Write-Host "Please Re-Run this script in a new powershell enviroment"
  Exit
}

# --------------------------------------------------------------------
# Define the variables.
# --------------------------------------------------------------------
$InetPubRoot = "D:\Inetpub"
$InetPubLog = "D:\Inetpub\Log"
$InetPubWWWRoot = "D:\Inetpub\WWWRoot"

# --------------------------------------------------------------------
# Loading Feature Installation Modules
# --------------------------------------------------------------------
Import-Module ServerManager 

# --------------------------------------------------------------------
# Installing IIS
# --------------------------------------------------------------------
Add-WindowsFeature -Name Web-Common-Http,Web-Asp-Net,Web-Net-Ext,Web-ISAPI-Ext,Web-ISAPI-Filter,Web-Http-Logging,Web-Request-Monitor,Web-Basic-Auth,Web-Windows-Auth,Web-Filtering,Web-Performance,Web-Mgmt-Console,Web-Mgmt-Compat,RSAT-Web-Server,WAS -IncludeAllSubFeature

# --------------------------------------------------------------------
# Loading IIS Modules
# --------------------------------------------------------------------
Import-Module WebAdministration

# --------------------------------------------------------------------
# Creating IIS Folder Structure
# --------------------------------------------------------------------
New-Item -Path $InetPubRoot -type directory -Force -ErrorAction SilentlyContinue
New-Item -Path $InetPubLog -type directory -Force -ErrorAction SilentlyContinue
New-Item -Path $InetPubWWWRoot -type directory -Force -ErrorAction SilentlyContinue

# --------------------------------------------------------------------
# Copying old WWW Root data to new folder
# --------------------------------------------------------------------
$InetPubOldLocation = @(get-website)[0].physicalPath.ToString()
$InetPubOldLocation =  $InetPubOldLocation.Replace("%SystemDrive%",$env:SystemDrive)
Copy-Item -Path $InetPubOldLocation -Destination $InetPubRoot -Force -Recurse

# --------------------------------------------------------------------
# Setting directory access
# --------------------------------------------------------------------
$Command = "icacls $InetPubWWWRoot /grant BUILTIN\IIS_IUSRS:(OI)(CI)(RX) BUILTIN\Users:(OI)(CI)(RX)"
cmd.exe /c $Command
$Command = "icacls $InetPubLog /grant ""NT SERVICE\TrustedInstaller"":(OI)(CI)(F)"
cmd.exe /c $Command

# --------------------------------------------------------------------
# Setting IIS Variables
# --------------------------------------------------------------------
#Changing Log Location
$Command = "%windir%\system32\inetsrv\appcmd set config -section:system.applicationHost/sites -siteDefaults.logfile.directory:$InetPubLog"
cmd.exe /c $Command
$Command = "%windir%\system32\inetsrv\appcmd set config -section:system.applicationHost/log -centralBinaryLogFile.directory:$InetPubLog"
cmd.exe /c $Command
$Command = "%windir%\system32\inetsrv\appcmd set config -section:system.applicationHost/log -centralW3CLogFile.directory:$InetPubLog"
cmd.exe /c $Command

#Changing the Default Website location
Set-ItemProperty 'IIS:\Sites\Default Web Site' -name physicalPath -value $InetPubWWWRoot
set-ItemProperty HKLM:\Software\Microsoft\InetStp\ -Name PathWWWRoot -Value $InetPubRoot
# -------------------------------------------------------------------- 
# Checking to prevent common errors 
# -------------------------------------------------------------------- 
If (!(Test-Path "C:\inetpub\temp\apppools")) { New-Item -Path "C:\inetpub\temp\apppools" -type directory -Force -ErrorAction SilentlyContinue } 
# -------------------------------------------------------------------- 
# Deleting Old WWWRoot 
# -------------------------------------------------------------------- 
Remove-Item $InetPubOldLocation -Recurse -Force 
# -------------------------------------------------------------------- 
# Resetting IIS 
# -------------------------------------------------------------------- 
$Command = "IISRESET" Invoke-Expression -Command $Command