Microsoft is preparing Windows 11 version 26H2, the next major feature update for Windows 11.

Although it is still a preview release, you can already download and install Windows 11 26H2 through the Windows Insider Program.

In this guide, I will show you two different ways to install it:

Downloading the official Windows 11 26H2 ISO
Installing Windows 11 26H2 through Windows Update

Before continuing, remember that Windows 11 26H2 is still an experimental build and may contain bugs, compatibility issues and unfinished features.

⚠️ I strongly recommend installing it on a virtual machine or separate test PC rather than your main everyday computer.

🪟 What Is Windows 11 26H2?

Windows 11 26H2 is the next major Windows 11 feature update currently being tested through the Windows Insider Program.

Current preview releases use the Windows 11 26300 build series.

Because Microsoft regularly releases new Insider builds, the exact build number you see may be newer than the one shown in my video.

At the time of recording, the builds demonstrated included:

Windows 11 Build 26300.8772
Windows 11 Build 26300.8935

The installation process should remain largely the same even if Microsoft releases a newer build.

✅ What You Will Need

Before getting started, make sure you have the following:

A Microsoft account
Access to the Windows Insider Program
A compatible Windows 11 PC or virtual machine
Enough free storage space
A stable internet connection
A backup of any important files

You may also need a USB flash drive if you plan to install Windows 11 26H2 on another computer.

⚠️ Important Warning Before Installing

Windows Insider builds are pre-release versions of Windows.

This means you may experience:

Software bugs
Driver problems
Application compatibility issues
System crashes
Reduced performance
Possible data loss

Do not install Windows 11 26H2 on a business-critical or production computer unless you fully understand the risks.

For most users, a virtual machine or spare PC is the safest option.

Method 1: Download the Windows 11 26H2 ISO

Downloading the ISO is useful if you want to:

Perform an in-place upgrade
Install Windows 11 26H2 on another computer
Create a bootable USB installer
Install Windows 11 26H2 in a virtual machine
Keep a copy of the installation media

👤 Step 1: Join the Windows Insider Program

Go to the official Microsoft Windows Insider Program website.

If you have not already joined the Insider Program, follow the registration steps shown on screen.

Microsoft may ask you to:

Accept the Insider Program agreement
Confirm your Microsoft account
Answer a few questions about how you plan to use preview builds

Once your account has been registered, remain signed in.

🌐 Step 2: Open the Windows Insider ISO Download Page

Go to Microsoft’s Windows Insider Preview ISO download page.

You must be signed in using the Microsoft account registered with the Windows Insider Program.

Scroll down the page until you see the option to select an edition.

If the download options do not appear, check that:

You are signed into the correct Microsoft account
Your account has joined the Windows Insider Program
You have accepted the required Insider agreements

📦 Step 3: Select the Windows 11 26H2 Build

Open the edition selection menu.

Look for a Windows 11 Insider Preview release using the 26300 build series.

The exact build number may vary depending on when you are following this guide.

Select the appropriate build and click Confirm.

Microsoft will validate your request and prepare the ISO download.

🌍 Step 4: Select Your Language

You will now be asked to choose the product language.

For users in the United Kingdom, select:

English International

Users in the United States can select:

English United States

Choose the correct language and click Confirm.

⬇️ Step 5: Download the ISO

Microsoft will now display a 64-bit Download button.

Click the button to begin downloading the Windows 11 ISO file.

The download may take some time because Windows ISO files are usually several gigabytes in size.

The total download time will depend on your internet connection.

Once complete, you can leave the ISO in your Downloads folder or move it to your desktop.

Installing Windows 11 26H2 Using the ISO

Once the ISO has downloaded, you have two main options:

Perform an in-place upgrade
Create a bootable USB installer

Option A: Perform an In-Place Upgrade

An in-place upgrade installs Windows 11 26H2 over your existing version of Windows.

It can allow you to keep:

Personal files
Installed applications
Windows settings

Even though your files should remain in place, always create a backup before upgrading.

💿 Step 1: Mount the ISO

Locate the downloaded ISO file.

Double-click the ISO.

Windows should automatically mount it as a virtual DVD drive.

You can find the mounted drive by opening File Explorer and selecting This PC.

The ISO should appear as a new drive, similar to a CD or DVD.

▶️ Step 2: Run Windows Setup

Open the mounted ISO drive.

Locate the file called:

setup.exe

Double-click the file.

If Windows displays a User Account Control prompt, click Yes.

The Windows 11 installer will now begin loading.

🔄 Step 3: Choose Whether to Download Updates

Windows Setup may ask whether you want to download updates, drivers and optional features during installation.

Leaving the recommended option enabled allows Windows Setup to check for compatibility updates.

Click Next.

The installer will then check for available updates.

📃 Step 4: Accept the Licence Terms

Read the Microsoft software licence terms.

Click Accept to continue.

Windows Setup will check whether your PC meets the installation requirements.

It may also download additional updates before continuing.

📁 Step 5: Confirm What You Want to Keep

Windows Setup will eventually display a screen titled:

Ready to install

Check that it says Windows will:

Install Windows 11
Keep personal files and apps

If the correct options are not displayed, click:

Change what to keep

Choose the option that keeps your files and applications.

Do not continue until you are happy with the selected options.

🚀 Step 6: Start the Installation

Click Install.

Windows will begin installing Windows 11 26H2.

Your computer may restart several times during the installation.

This is completely normal.

Do not turn off the computer while the upgrade is taking place.

Once the installation has completed, Windows should return you to the desktop.

Option B: Create a Bootable USB Installer

You can also use the ISO to install Windows 11 26H2 on another computer.

For this, you will need to create a bootable USB flash drive.

One of the easiest tools to use is Rufus.

⚠️ Creating a bootable USB will normally erase everything stored on the USB drive.

Make sure you copy any important files from the USB before continuing.

🔧 Creating the USB with Rufus

The basic process is:

Connect your USB flash drive.
Open Rufus.
Select the correct USB drive under Device.
Choose the Windows 11 26H2 ISO.
Check the partition and target system settings.
Click Start.
Wait for Rufus to create the installation media.

Rufus may display options that allow you to bypass certain Windows 11 requirements.

These may include removing requirements such as:

TPM
Secure Boot
Microsoft account sign-in
Minimum RAM

These bypass options may not work correctly with all experimental builds.

Use them at your own risk.

Once the USB has been created, connect it to the test computer and boot from the USB drive.

You may need to open the computer’s boot menu or change the boot order in the UEFI or BIOS settings.

Method 2: Install Windows 11 26H2 Through Windows Update

You can also install Windows 11 26H2 directly through the Windows 11 Settings app.

This method does not require you to download an ISO manually.

👤 Step 1: Register Your Microsoft Account

Make sure your Microsoft account is registered with the Windows Insider Program.

You can use your normal Microsoft account or create a separate testing account.

Using a separate account may be useful if you do not want to connect your main Microsoft account to an experimental computer.

⚙️ Step 2: Open the Windows Insider Settings

Open the Windows 11 Start menu.

Search for:

Settings

Open the Settings app.

Select:

Windows Update

Scroll down and select:

Windows Insider Program

Click:

Get started

🔗 Step 3: Link Your Microsoft Account

Windows will ask you to link an account.

Click:

Link an account

Once the account has been linked, Windows will show the available Insider channels.

🧪 Step 4: Select the Experimental or Dev Channel

Choose the channel containing the Windows 11 26H2 preview builds.

Depending on the version of Windows and the current Microsoft naming, this may appear as:

Experimental Channel
Dev Channel

Select the relevant channel and click Continue.

Windows will display a warning explaining that these builds may have reduced stability and unfinished features.

Read the information carefully before proceeding.

🔁 Step 5: Accept the Agreement and Restart

Accept the Windows Insider agreement.

Windows will then ask you to restart the computer.

Save any open work.

Click:

Restart now

Your computer will restart and complete the Insider Program enrolment.

🔍 Step 6: Check for Updates

Once the computer has restarted, open:

Settings > Windows Update

Click:

Check for updates

Windows should begin searching for the latest Insider Preview build.

If the correct channel has been selected, Windows should offer a 26300 series build.

Click the download or install option if required.

The update may take some time to download and install.

Your computer may restart multiple times during the process.

🔎 How to Check That Windows 11 26H2 Is Installed

After the installation has completed, you can confirm the version in two ways.

Method 1: Check Through Windows Settings

Open:

Settings > System > About

Scroll down to:

Windows specifications

You should see information including:

Edition
Version
Installation date
OS build

The version should show:

26H2

You should also see a build number from the 26300 series or a newer related build.

Method 2: Check Using Winver

You can also check the installed version using the Windows version command.

Click the Windows search box and type:

winver

Open the result.

The About Windows box should display:

Windows 11
Version 26H2
The installed OS build

This is one of the quickest ways to check which Windows version you are running.

🛠️ Troubleshooting Common Problems

The ISO Download Is Not Available

Make sure you are signed in using the Microsoft account registered with the Windows Insider Program.

You may also need to:

Refresh the page
Sign out and back in
Accept the latest Insider agreement
Try another browser

Windows 11 26H2 Is Not Appearing in Windows Update

Check that:

Your Microsoft account is linked correctly
You joined the correct Insider channel
Windows Update is not paused
You restarted the computer after joining
Your PC meets the required hardware specifications

Return to:

Settings > Windows Update > Windows Insider Program

Confirm that the correct channel is selected.

Windows Setup Will Not Keep My Files and Applications

This can happen when:

The ISO language does not match the current Windows language
You selected an incompatible Windows edition
You booted from the USB instead of opening setup.exe inside Windows
The installed version cannot be upgraded using that build

Cancel the installation and check the ISO language and edition.

To keep files and applications, launch setup.exe from inside your existing Windows installation.

The Installation Appears to Be Stuck

Windows feature updates can sometimes remain on the same percentage for a long time.

This is especially common on:

Older computers
Devices with slower storage
Virtual machines with limited resources
Computers downloading updates during setup

Avoid forcing the computer to shut down unless you are certain the installation has completely stopped responding.

Interrupting Windows Setup could corrupt the installation.

🚪 Can You Leave the Insider Program Later?

Before joining an early Insider channel, it is important to consider how you will return to a stable version of Windows.

Depending on the build installed, Microsoft may not allow you to immediately switch to a more stable Insider channel.

In some cases, returning to the public release of Windows may require a clean installation.

This is why Windows 11 26H2 should ideally be tested on:

A virtual machine
A spare laptop
A test desktop
Non-production hardware

💡 Final Thoughts

Installing Windows 11 26H2 gives you early access to upcoming Windows features and platform changes.

The easiest method is to enrol a test computer through:

Settings > Windows Update > Windows Insider Program

Downloading the ISO gives you more flexibility if you want to:

Create a virtual machine
Perform an in-place upgrade
Install Windows on another PC
Create bootable USB media

Whichever method you choose, remember that this is still a preview version of Windows.

Always keep a backup and avoid installing experimental builds on a device you rely on every day.

For a complete visual walkthrough, watch my accompanying YouTube video where I demonstrate both installation methods and show you how to confirm Windows 11 26H2 has installed correctly.

Have you tried Windows 11 26H2 yet?

Let me know what you think and whether you have discovered any interesting new features.

❓ Frequently Asked Questions

Is Windows 11 26H2 available to everyone?

Windows 11 26H2 is currently available as a preview through the Windows Insider Program.

It is not yet the standard public Windows 11 update for all users.

Which Insider channel includes Windows 11 26H2?

Windows 11 26H2 preview builds are available through Microsoft’s early development channels.

Depending on Microsoft’s current naming, this may appear as the Experimental Channel or Dev Channel.

Is Windows 11 26H2 stable?

Windows 11 26H2 preview builds are designed for testing.

They may contain bugs, compatibility problems and unfinished features.

They should not be treated as stable production releases.

Can I keep my files when installing from the ISO?

Yes.

If you open the ISO inside Windows and run setup.exe, you should normally have the option to keep your files and installed applications.

Always check the Ready to install screen before clicking Install.

Can I install Windows 11 26H2 in a virtual machine?

Yes.

A virtual machine is one of the safest ways to test Windows 11 26H2 without affecting your main computer.

Do I need a Windows product key?

If you perform an in-place upgrade on an already activated Windows computer, the activation should normally remain in place.

A clean installation may require a valid Windows licence depending on the computer and its previous activation status.