Windows 11 is free to download from Microsoft. What you pay for is the licence that activates it. This guide shows the safe way to get the current version – the Windows 11 2026 Update (version 26H2), released on 29 September 2026 – as an ISO file, on a USB stick or as an in-place upgrade, and how to activate it with your product key.
It also covers the activation errors people run into most often, and what to do if your PC still runs version 24H2, which stops receiving security updates after 13 October 2026.
The short answer
- Download Windows 11 only from Microsoft’s official page, microsoft.com/software-download/windows11. It offers the Installation Assistant, the Media Creation Tool and the ISO file.
- There is one download for Home and Pro. Your product key decides which edition is installed and activated.
- To activate, open Settings → System → Activation → Change product key and enter your 25-character key.
- Reinstalling a PC that was activated before? Choose “I don’t have a product key”. Windows usually reactivates itself with its digital licence.
- Still on version 24H2? Home and Pro lose security updates after 13 October 2026. Update to 26H2 through Windows Update or the Installation Assistant.
Which Windows 11 download do you need?
| Option | Best for | What you need |
|---|---|---|
| Installation Assistant | Upgrading the PC you are using from Windows 10, or updating Windows 11 to the latest version | Windows 10 version 2004 or later, 9 GB of free space, an x64 PC |
| Media Creation Tool | A bootable USB stick for a clean install, a new build or another PC | A USB stick with at least 8 GB (it will be erased), an x64 PC |
| ISO file (disk image) | Virtual machines, upgrading by mounting the file, or creating a USB stick with another tool | Several gigabytes of free space, an x64 PC |
All three install the same Windows 11. For PCs with an Arm processor, such as many Snapdragon laptops, Microsoft offers a separate Arm64 download.
Before you start: a five-point checklist
- Check the hardware. Windows 11 needs a compatible 64-bit processor with at least two cores, 4 GB of RAM, 64 GB of storage, UEFI firmware with Secure Boot and TPM 2.0. Microsoft’s free PC Health Check app tells you within a minute whether your PC qualifies.
- Back up your files. A clean install erases the drive you install on. An upgrade keeps files and apps, but a backup is still wise.
- Have your product key ready. A Windows product key has 25 characters in the format XXXXX-XXXXX-XXXXX-XXXXX-XXXXX. Keep the email or document with your key at hand.
- Use a USB stick with at least 8 GB if you want installation media. Everything on it will be deleted.
- Plan for internet access and a Microsoft account. Microsoft requires both during the first setup of Windows 11 Home and of Windows 11 Pro for personal use.
How to create a Windows 11 USB stick with the Media Creation Tool
- Open microsoft.com/software-download/windows11 and, under Create Windows 11 Installation Media, select Download now.
- Run the downloaded tool. You need administrator rights. Accept the licence terms.
- Choose the language and edition, or keep the recommended options for this PC. The edition called “Windows 11” contains both Home and Pro.
- Select USB flash drive, pick your stick and select Next. The tool downloads Windows 11 and makes the stick bootable. Depending on your connection, this can take a while.
How to download the Windows 11 ISO file
- On the same Microsoft page, go to Download Windows 11 Disk Image (ISO) for x64 devices and select Windows 11 (multi-edition ISO for x64 devices).
- Select Download now, choose the product language and confirm.
- Select the 64-bit download. The link is valid for 24 hours.
- Optional but sensible: compare the file’s SHA-256 checksum with the values Microsoft lists under Verify your download. In PowerShell, run
Get-FileHashfollowed by the path to the ISO file.
What you can do with the ISO:
- Upgrade the PC you are using: double-click the ISO to mount it as a virtual drive, then run setup.exe. You can choose to keep your files and apps.
- Install Windows 11 in a virtual machine: Hyper-V (included in Windows 11 Pro), VirtualBox and VMware use the ISO directly. Windows in a virtual machine needs to be activated like any other installation.
- Create a USB stick with another tool: possible, but the Media Creation Tool is the simplest route for most people.
How to install Windows 11 from the USB stick
- Plug in the stick and restart the PC. Open the boot menu – depending on the manufacturer usually with F12, F11, F8 or Esc right after switching on – and choose the USB stick.
- Choose language, time format and keyboard, then choose to install Windows 11.
- When setup asks for a product key, enter it. If you are reinstalling a PC that was activated before, select I don’t have a product key.
- If setup asks you to pick an edition, choose the one that matches your licence: Home or Pro.
- Choose the drive to install on. A clean install deletes everything on that drive.
- Follow the setup screens for region, keyboard, network and Microsoft account.
Tip: If your PC came with Windows 11 Home, setup may install Home without asking, because the original key is stored in the PC’s firmware. That is normal. Finish setup, then enter your Pro key as described below to upgrade.
How to activate Windows 11 with a product key
If you did not enter the key during setup:
- Open Settings → System → Activation.
- Next to Change product key, select Change.
- Enter the 25-character key, select Next and then Activate.
Check the status on the same page. “Windows is activated” or “Windows is activated with a digital license” means you are done.
Upgrade from Windows 11 Home to Pro
Enter your Windows 11 Pro key in the same place: Settings → System → Activation → Change product key. Windows switches to Pro after a restart and keeps your files and apps. Microsoft notes that this works on PCs running an activated copy of Windows 11 Home. Not sure whether you need Pro? Our guide to Windows 11 Pro vs Home explains the differences.
Link your licence to your Microsoft account
When you sign in with a Microsoft account, Windows links the digital licence to it. The Activation page then shows “Windows is activated with a digital license linked to your Microsoft account”. That makes reactivation much easier after a major hardware change such as a new motherboard: on the Activation page, select Troubleshoot and then I changed hardware on this device recently.
If Settings does not accept the key
Open Terminal (Admin) and run slmgr /ipk followed by your key, then slmgr /ato to activate online.
Common Windows 11 activation errors and how to fix them
| Error | What it means | What to do |
|---|---|---|
| 0xC004F050 | The key cannot be used to activate this installation – often a typo, or a key for a different edition, such as a Home key on a Pro installation. | Check the key. If the editions do not match, install the edition your key is for. |
| 0xC004C003 | The activation servers did not accept the key as valid. | Check for typos and try again later. If it persists, contact the seller with a screenshot. |
| 0xC004C008 | The key has already been used on another PC, or on more PCs than allowed. | Use one key per PC. After a hardware change, run the activation troubleshooter. |
| 0xC004F213 | Windows found no product key on this PC – typical after a motherboard replacement. | Enter your key, or run the troubleshooter if your licence is linked to your Microsoft account. |
| 0x803F7001 | No valid Windows 11 licence was found. | Enter a valid product key under Change product key. |
Bought your key from TheUnitySoft and activation fails? Contact our support team with the error code and a screenshot of Settings → System → Activation, and we will help you get Windows activated.
Still on version 24H2? Update to 26H2
Microsoft supports each Windows 11 version for Home and Pro for 24 months. Version 24H2 reaches the end of servicing on 13 October 2026, version 25H2 in October 2027 and the new version 26H2 in October 2028. To check your version, press the Windows key and R, type winver and press Enter.
From 24H2 or 25H2, the update to 26H2 is a small enablement package that needs a single restart, offered in Windows Update. If it does not appear yet, the Installation Assistant installs the latest version. Still on Windows 10? Read what the extended Windows 10 security updates mean for you.
Need a Windows 11 licence?
For a new build, a clean install on a PC without a licence or the step up from Home to Pro, you need a genuine Windows 11 product key. TheUnitySoft delivers it by email straight after payment, with step-by-step activation instructions.
Windows 11 Pro → · Windows 11 Home → · All Windows licences →
Frequently asked questions
Is it safe and legal to download the Windows 11 ISO?
Yes, if you download it from Microsoft. Microsoft offers the ISO, the Media Creation Tool and the Installation Assistant free of charge. To use Windows 11, you need a valid licence that activates it. Avoid ISO files from other websites, because they can be modified.
Is there a separate download for Windows 11 Home and Pro?
No. The official multi-edition ISO contains both editions. The product key decides which edition is installed and activated.
Can I install Windows 11 without a product key?
Yes, setup lets you skip the key. Windows then stays unactivated until you enter a valid key: it keeps reminding you to activate, and some personalisation settings are locked. A PC that was activated before reactivates itself automatically.
Do I need a new key after reinstalling Windows 11?
Usually not. If the PC was activated before, Windows recognises its digital licence and activates online after setup. Install the same edition, Home or Pro, that was activated before.
What is the latest version of Windows 11?
The Windows 11 2026 Update, version 26H2, released on 29 September 2026. Microsoft’s ISO, Media Creation Tool and Installation Assistant deliver this version.
Can I install Windows 11 on a PC that does not meet the requirements?
Microsoft does not recommend it, and such PCs are not guaranteed to receive updates. If your PC fails the check only because TPM or Secure Boot is switched off, turn them on in the UEFI settings and check again.
Sources: Microsoft – Download Windows 11, Microsoft Support – Activate Windows, Microsoft Support – Windows activation errors, Microsoft Support – Upgrade Windows Home to Pro, Microsoft – Windows 11 specifications, Microsoft Lifecycle – Windows 11 Home and Pro. Last updated: 12 October 2026.
