You went to download Windows 11 and found three buttons on one page, all official, none of them explaining which one is yours. That is where most of the confusion starts.
They do genuinely different jobs, and picking the wrong one wastes an evening. It is not a case of any of them being better.
I have taken them by what you are actually trying to do, which is the ordering that page does not use.
The three, and the one line that separates them
Everything below is detail. This is the decision.
Documented by Microsoft on its Windows 11 download page, the Installation Assistant is "the best option for installing Windows 11 on the device you're currently using."
The Media Creation Tool is for when "you want to perform a reinstall or clean install of Windows 11 on a new or used PC", making "a bootable USB or DVD".
The ISO is "for users that want to create a bootable installation media (USB flash drive, DVD) or create a virtual machine".
⭐ Upgrading this machine, right now, in place? Installation Assistant. Everything else is more work than you need.
⚡ Putting Windows on a different machine? Media Creation Tool, which makes the USB stick for you.
⛔ The ISO is the specialist option. Take it only if you already know why you want a file rather than a stick.
What each one needs before it will run
The requirements are real and Microsoft prints them. Worth reading before the download, not after.
For the Installation Assistant, Microsoft states three things: "You have a Windows 10/11 license", "Your PC must have Windows 10, version 2004 or higher installed", and "Your PC must have 9 GB of free disk space to download Windows 11."
⚠️ And a limit that catches people on newer laptops: it "doesn't run on Arm-based PCs; it only works for x64 processors."
⭐ For the Media Creation Tool, you need a machine with "a 64-bit CPU" and either a USB stick or "a blank DVD disc with at least 8GB".
⚡ Nine gigabytes free is more than people expect. If that is the part stopping you, there is an order to freeing it up.
Microsoft's own warning about unsupported PCs
Printed on the page, and worth quoting rather than paraphrasing.
In Microsoft's words: "Installing Windows 11 media on a PC that does not meet the Windows 11 minimum system requirements is not recommended and may result in compatibility issues."
⛔ Not blocked. Not recommended. Those are different things, and the wording is deliberate.
⭐ Check whether your PC qualifies before you download anything. The requirement that stops most machines is one setting rather than the hardware, and it is often switched off rather than missing.
Do not download from anywhere else
Short, and the most important paragraph on this page.
⛔ Windows installation media comes from microsoft.com and nowhere else. Search results carry paid listings and lookalike domains, and an installer from one of those is a real risk.
⭐ Ours, and marked as ours: type the address rather than searching for it. Any page asking you to pay for the download, or to install a downloader first, is not Microsoft.
⚠️ The file is large and it should be. A Windows 11 ISO that arrives in seconds is not a Windows 11 ISO.
Checking what you already have, and a trap in doing it
Useful, because half the people downloading this already have Windows 11.
Hit Windows and R, put in `winver`, press Enter. That names the version and the build in one small box.
⛔ Ours, and read from a machine here. The registry key that names the product still says Windows 10 Home on a machine running Windows 11 version 25H2, build 26200.
⭐ So a registry check answers the wrong question. Microsoft never updated that value. Any instruction telling you to read it is quietly wrong on Windows 11.
⚡ Use winver, or Settings, System, About instead. The wider version of that check names your processor and memory too.
The Windows 10 versions of the same three
Worth knowing, because the pages look identical and the tools are not interchangeable.
⭐ Windows 10 has its own Media Creation Tool and its own ISO, on a separate Microsoft page. A Windows 11 tool will not produce Windows 10 media.
⚠️ There is no Windows 10 Installation Assistant in the same sense. The upgrade path from an older Windows 10 build runs through Windows Update instead.
⚡ Ours: if you are making a rescue USB to keep in a drawer, make it for the version the machine is on now. A stick made for the wrong one is worse than no stick.
When you do not need any of this
Being useful rather than helpful, because the download is often the wrong step.
⛔ A machine that boots but misbehaves does not need installation media. Reset is built in, keeps your files, and does not need a USB stick at all.
⭐ Ours, and marked as ours: try the reinstall that is already on your drive first. Most people who download a tool never needed one.
⚡ A stuck update is not a reason to reinstall either. That has its own order and it is far shorter.
What to do with the stick afterwards
Practical, and the part the download page skips entirely.
⭐ Label it with the version and the date. Windows media ages, and a stick made two years ago installs a two year old build that then has to update itself for an hour.
⚠️ Keep it out of the machine on a normal restart. A PC set to boot from USB first will start the installer instead of Windows, which looks like a much bigger problem than it is.
⚡ Ours: remake the stick once a year if you keep one. It takes twenty minutes and it saves an hour of updates on the day you actually need it.
Status: read off Microsoft's own download page 24 August 2026. The three tool descriptions, the licence, version 2004 and 9 GB requirements, the Arm limitation, the 64-bit and 8 GB media requirements, and the wording about unsupported PCs are all quoted from that page. The registry naming a Windows 11 machine as Windows 10 Home was read here on build 26200.
Which Windows 11 download do I need?
Upgrading the PC you are sitting at, use the Installation Assistant. Installing on a different or empty machine, use the Media Creation Tool to make a USB stick. Take the ISO only if you specifically want a file, for a virtual machine or your own media.
Do I need a product key to download Windows 11?
Not to download it. Microsoft states the Installation Assistant needs you to have a Windows 10 or 11 licence, which is usually already tied to the machine. Activation and download are separate steps and the download itself is free.
Can I install Windows 11 on an unsupported PC?
Microsoft does not block the media, but it says installing on a PC that does not meet the minimum requirements "is not recommended and may result in compatibility issues". That wording is deliberate. Check the requirements first, because the usual blocker is a setting rather than missing hardware.
Why does my registry say Windows 10 when I have Windows 11?
Because Microsoft never changed that value. On a machine here running Windows 11 version 25H2, the registry still reports Windows 10 Home. Use winver, or Settings, System, About, which both report correctly.
The Short Version
- Installation Assistant upgrades the machine you are using. That is the common case.
- Media Creation Tool makes a bootable USB or DVD for a different machine.
- The ISO is for a virtual machine or your own media. Take it only if you know why.
- Microsoft requires a licence, Windows 10 version 2004 or higher, and 9 GB free.
- The Installation Assistant does not run on Arm-based PCs, only x64.
- Unsupported PCs are not blocked. Microsoft says it is not recommended, which is different.
- Download only from microsoft.com. Search results carry lookalikes and paid listings.
- The registry still names Windows 11 machines as Windows 10. Use winver instead.
Where to Next
Decide which of the three you need before you click anything. Upgrading this machine is the Installation Assistant, and that covers most people who land on that page.
If the machine boots and simply misbehaves, do not download anything at all. Reset is already on the drive and it keeps your files.
Run winver first either way. It takes five seconds and it stops you installing something you already have.
And if you made a rescue stick and it turned out to be the wrong version when you needed it, tell me what happened in the comments. That mistake is common and almost nobody writes it down.
Isaac Smith is the founder and editor of PC Glance, a website that covers computers, laptops, and technology. He is a tech enthusiast and a computer geek who loves to share his insights and help his readers make smart choices when buying tech gadgets or laptops. He is always curious and updated about the latest tech trends.