How to Install .NET Framework 4 Using PowerShell

As IT operations have evolved and become more intricate, automation has established itself as a cornerstone. One can’t overlook the significance of scripting, especially PowerShell, in modern IT infrastructures. PowerShell, with its ability to automate and streamline tasks, has become indispensable. Today, we discuss a specific PowerShell script designed to install the .NET Framework 4, an essential foundation for many applications.

Background

The .NET Framework by Microsoft acts as a software development platform, providing services, libraries, and tools needed to develop and run a vast array of applications. It’s paramount for IT professionals and Managed Service Providers (MSPs) to have an efficient method of installing this framework, ensuring that applications run seamlessly. Our PowerShell script serves this purpose with added functionalities, such as the ability to install from an offline source.

The Script

#Requires -Version 5.1

<#
.SYNOPSIS
    Install NetFx4 features(.NET 4.x), with the option to install from an offline source.
.DESCRIPTION
    Install NetFx4 features(.NET 4.x), with the option to install from an offline source.
    An offline source can be an attached CD/DVD image of the OS's installer.
.EXAMPLE
     No parameters needed.
    Install NetFx4 features from Local Install/Windows Update/WSUS.
.EXAMPLE
     -OfflineSource "D:sourcessxs"
    Install NetFx4 features from a specified source.
.EXAMPLE
    PS C:> Install-DotNet4.ps1
    Install NetFx4 features from Local Install/Windows Update/WSUS.
.EXAMPLE
    PS C:> Install-DotNet4.ps1 -OfflineSource "D:sourcessxs"
    Install NetFx4 features from a specified source.
.OUTPUTS
    None
.NOTES
    General notes
    Release Notes:
    Initial Release
By using this script, you indicate your acceptance of the following legal terms as well as our Terms of Use at https://www.ninjaone.com/terms-of-use.
    Ownership Rights: NinjaOne owns and will continue to own all right, title, and interest in and to the script (including the copyright). NinjaOne is giving you a limited license to use the script in accordance with these legal terms. 
    Use Limitation: You may only use the script for your legitimate personal or internal business purposes, and you may not share the script with another party. 
    Republication Prohibition: Under no circumstances are you permitted to re-publish the script in any script library or website belonging to or under the control of any other software provider. 
    Warranty Disclaimer: The script is provided “as is” and “as available”, without warranty of any kind. NinjaOne makes no promise or guarantee that the script will be free from defects or that it will meet your specific needs or expectations. 
    Assumption of Risk: Your use of the script is at your own risk. You acknowledge that there are certain inherent risks in using the script, and you understand and assume each of those risks. 
    Waiver and Release: You will not hold NinjaOne responsible for any adverse or unintended consequences resulting from your use of the script, and you waive any legal or equitable rights or remedies you may have against NinjaOne relating to your use of the script. 
    EULA: If you are a NinjaOne customer, your use of the script is subject to the End User License Agreement applicable to you (EULA).
#>

[CmdletBinding()]
param (
    [Parameter()]
    [String]
    $OfflineSource
)

begin {
    $OSVersion = [System.Environment]::OSVersion.Version
}
process {
    if ($OSVersion -gt [Version]::new(6, 2)) {
        # Windows 8.1/Server 2012 R2 or greater
        $Packages = dism /Online /Get-Features /Format:Table
        if ($OfflineSource) {
            # Install .NET 3 and 4
            if ((Test-Path -Path $OfflineSource -ErrorAction SilentlyContinue)) {
                if ($($Packages | Select-String -Pattern "NetFx4" | Select-Object -First 1) -like "Disabled") {
                    dism /Online /Enable-Feature /FeatureName:NetFx4 /All /Source:$OfflineSource
                }
            }
            else {
                Write-Error "Path to $OfflineSource doesn't exist."
            }
        }
        else {
            if ($($Packages | Select-String -Pattern "NetFx4" | Select-Object -First 1) -like "Disabled") {
                dism /Online /Enable-Feature /FeatureName:NetFx4 /All
            }
        }
    }
    else {
        # Windows 8/Server 2012 or lesser
        # This requires copying the installer to the target in some way; either by downloading or shared folder as examples.
        Write-Output "More Info: https://ninjarmm.zendesk.com/hc/en-us/articles/360043992771-How-to-install-software-outside-of-3rd-Party-Patching"
        Write-Error "Use the Install Application script to install dotNetFx40_Full_x86_x64.exe"

        # The code below is an example of downloading, but isn't guarantied to work 100%.

        # Invoke-WebRequest -Uri "http://download.microsoft.com/download/9/5/A/95A9616B-7A37-4AF6-BC36-D6EA96C8DAAE/dotNetFx40_Full_x86_x64.exe" -OutFile "dotNetFx40_Full_x86_x64.exe"
        # dotNetFx40_Full_x86_x64.exe /q: http://download.microsoft.com/download/9/5/A/95A9616B-7A37-4AF6-BC36-D6EA96C8DAAE/dotNetFx40_Full_x86_x64.exe
        # Remove-Item -Path "dotNetFx40_Full_x86_x64.exe"
    }
}
end {}

 

Detailed Breakdown

Let’s delve into the core components of this script: 

• Parameters: The script begins by setting up a parameter $OfflineSource. If provided, it lets users install the framework using a source different from the default (like a local source). 
• Environment Check: It retrieves the current Operating System’s version. 
• Process: 
• If the OS version is greater than Windows 8.1/Server 2012 R2, it checks for available packages. 
• Depending on the $OfflineSource parameter, it uses either the local source or the default one to install the framework. 
• For OS versions less than Windows 8/Server 2012, the script offers a guideline for installation, suggesting a manual download method. 

Potential Use Cases

Scenario: Imagine James, an IT administrator for a mid-sized company. They’re migrating some legacy apps to a newer environment, requiring .NET Framework 4 on all servers. Some servers have restricted online access, so an offline installation is necessary. Using this script, James can streamline the installation across multiple servers, saving time and ensuring uniformity. 

Comparisons

Traditional installation of .NET Framework might involve manually downloading the installer and going through the setup, or using Windows Feature installation. Our script offers advantages: 

• Automation: Schedule or instantly deploy across multiple servers. 
• Flexibility: Choose between online and offline installation. 
• Error Checks: Provides specific feedback if something doesn’t go as planned. 

FAQs

• Can I use this script for versions other than .NET Framework 4?
  This script is specifically designed for .NET Framework 4. Modifications would be needed for other versions. 
• How do I ensure my offline source is correct?
  Ensure the path provided to the $OfflineSource parameter points to the correct installation files. 

Implications

When automating installations, especially with scripts that modify system settings, there’s an inherent risk. An erroneous installation could lead to system vulnerabilities. It’s essential to understand the script thoroughly and test it in a controlled environment before broad deployment. 

Recommendations

• Always back up your system before running scripts that modify system configurations. 
• If using an offline source, ensure it’s from a trusted and legitimate supplier. 
• Regularly update the script to cater to newer OS versions or updates to the .NET Framework. 

Final Thoughts

In today’s IT landscape, leveraging tools like NinjaOne has become crucial. As we’ve seen with this .NET installation script, automation can simplify intricate tasks. NinjaOne’s comprehensive platform can aid in the effective deployment and management of such scripts, ensuring IT operations remain smooth and efficient.