Automate IIS enable on Windows 7.

Background

There are plenty of sites that will tell you how to enable IIS through the Control Panel. Although, if you are tasked with enabling IIS automatically (eg. for an installer), it can be a nightmare. This is only really needed though in special cases where the installer has more control over the hardware specifications. Determining an upgrade or uninstall scenario with IIS can be very tough since you are not installing your own software but rather enabling a feature of Windows. With that in mind, we can propose a solution for automated enabling of IIS.

Requirements

Windows Editions

The edition of Windows 7 for IIS must be either Ultimate or Professional if you plan on using ASP.NET. You can try this on other editions, or even Vista, but your results may differ since this is only scenario I have tested against. More information can be found at the IIS TechNet site.

DISM Tool

To enable IIS features through the command line, DISM can be used. This can be reliably found on Windows 7 but is inconsistent on Vista, where the older Package Manager is used instead. This was one of the reasons I decided to constrain the specification to Windows 7.

The first step in using DISM, is to find out which features need to be enabled, in order for IIS to work completely. I ran across this MSDN blog entry that lists all the needed features. Next task is to script the DISM commands.

Scripting

Caveats

Iterating over each feature and enabling it with DISM can be very time consuming. The faster approach is to evaluate the enabled state of each feature and turn them all on in one command. PowerShell can be used but the presence of it and its needed modules can be inconsistent on Windows 7. I had to fall back on batch scripting, which is the part that can cause nightmares due to its ugly syntax.

Arrays are need to store the enabled states of each feature and the feature names themselves. In my case, I needed an array of pairs. I was able to fake it using a suggestion on Stack Overflow. Also, special syntax is needed to reference variables inside a loop that are scoped outside the loop.

Last, but not least, remember to register the ASP.NET framework version being used with IIS. This will need to be done once IIS is enabled (reboot is required). Adjust the framework bitness and version below according to the one you are using.

[WindowsFolder]\Microsoft.NET\Framework64\v4.0.30319\aspnet_regiis.exe -i

The Code

The following batch script will discover which features are disabled, concatenate them into the enable command and then execute. You may need to replace SysNative with system32 or the Windows system folder being used by your target system if this is being ran outside the installer.

setlocal enableextensions enabledelayedexpansion
set features=IIS-ApplicationDevelopment IIS-ASPNET IIS-CommonHttpFeatures IIS-HostableWebCore IIS-HttpCompressionDynamic IIS-HttpCompressionStatic IIS-HttpErrors IIS-HttpLogging IIS-HttpRedirect IIS-HttpTracing IIS-Metabase IIS-NetFxExtensibility IIS-Performance IIS-StaticContent IIS-URLAuthorization IIS-WebServerRole WAS-ConfigurationAPI WAS-NetFxEnvironment WAS-ProcessModel WAS-WindowsActivationService
set dism_params=

set n=0
for %%f in (%features%) do (
 set /a n+=1
 set dism_params=!dism_params! /FeatureName:%%f
 set features[!n!]=%%f
)
set n=0
for /f "tokens=3*" %%i in ('%WINDIR%\SysNative\Dism.exe /Online /Get-FeatureInfo %dism_params% ^| findstr /b /r "^State : "') do (
 set /a n+=1
 set states[!n!]=%%i
)

set dism_params=
for /l %%i in (1,1,%n%) do (
 if "!states[%%i]!" == "Disabled" set dism_params=!dism_params! /FeatureName:!features[%%i]!
)

if "%dism_params%" neq "" %WINDIR%\SysNative\Dism.exe /Online /Enable-Feature %dism_params%