Upgrading to Windows 11 is usually straightforward, but it is not a single click you should rush. The upgrade replaces core system files, restarts your PC several times, and can take an hour or more depending on the machine. A little preparation prevents most of the problems people run into.
This guide covers the safe order of work: confirm your PC is supported, back up your data, then upgrade using the official Microsoft routes. It also explains what to do when the upgrade option never appears, when it fails and rolls back, and when an unsupported PC is genuinely a bad idea.
Before you start: the three things that matter
Windows 11 has firm hardware requirements, and Microsoft has not relaxed them for general upgrades. Before touching anything, make sure you have:
- A supported PC. Windows 11 requires a compatible 64-bit processor, TPM version 2.0, UEFI firmware with Secure Boot capability, and at least 4 GB of RAM. Microsoft lists 64 GB as the minimum storage device size, but that is not the same as the free space you need to perform the upgrade. In practice you want a comfortable amount of free space on the system drive before starting, because the upgrade downloads and stages a large amount of data.
- A current backup. Not a copy of a few folders — a proper backup of anything you could not bear to lose.
- Mains power and time. Use a laptop on mains power, not battery. Do not start an upgrade when you need the machine in the next hour.
If your PC is still on Windows 10, be clear about where you stand. Standard support for Windows 10 ended on 14 October 2025. Extended Security Updates (ESU) are a separate programme with their own eligibility rules — being eligible for ESU is not the same as being in general support, and it does not make Windows 10 a long-term home. Upgrading to Windows 11, where the hardware allows it, is the cleaner path.
Step 1: Check whether your PC meets the Windows 11 requirements
Microsoft provides a free tool called PC Health Check that reports whether your specific machine is compatible and, if not, which requirement is failing. Download it from Microsoft's official Windows 11 page and run it.
If you prefer to check manually, you can confirm the processor model in Settings > System > About and check TPM status using the Trusted Platform Module Management console (tpm.msc). The PC Health Check result is easier to interpret, so start there.
If the tool says your PC is not supported, stop and read the section on unsupported PCs below before going any further. Do not try to force the upgrade on a machine that fails the checks without understanding the risks.
Step 2: Back up your important files
An in-place upgrade is designed to keep your files, apps and settings, and most of the time it does. But "most of the time" is not a backup strategy. Upgrades can fail partway through, a drive can develop problems under sustained write load, and rollbacks are not always clean.
At minimum, copy your documents, photos, accounts and anything business-critical to an external drive or a cloud service, and verify the copies open. If you want a more structured approach, our guide to SSD vs HDD failure signs and a complete data backup strategy explains how to build a backup you can actually rely on.
If your drive is already making unusual noises, running very slowly, or showing warnings, do not upgrade yet. Deal with the storage problem first — our data recovery advice for failing storage covers the safe next steps.
Step 3: Upgrade through Windows Update
This is the route Microsoft prefers, and it is the least error-prone for a supported PC.
- Open Settings (Start > Settings, or press Windows key + I).
- Go to Windows Update.
- Select Check for updates.
- Install any pending updates first, including cumulative updates and driver updates. A fully patched Windows 10 is a better starting point.
- If the upgrade to Windows 11 is offered, it will appear as an option in Windows Update. Follow the prompts to download and install it.
The upgrade will restart your PC several times. Let it finish without interrupting it, and do not unplug a laptop or switch off a desktop mid-install.
Step 4: Alternative — the Windows 11 Installation Assistant
If Windows Update does not offer the upgrade but PC Health Check confirms your PC is supported, Microsoft's Installation Assistant is the official alternative. It is a small downloadable tool from Microsoft's Windows 11 page that performs the same in-place upgrade.
Download it only from Microsoft's own site, run it, accept the prompts, and let it work. Avoid third-party "upgrade tools" or modified installers — they add risk for no benefit on a supported machine.
If the upgrade option doesn't appear in Windows Update
This is common and usually not a fault. Microsoft rolls out upgrades in phases, so a supported PC may simply not be offered it yet. Other frequent causes:
- Pending updates. Install everything Windows Update is offering, restart, then check again.
- Outdated Windows 10 build. Very old builds may need to be brought up to date before the upgrade is offered.
- Blocking drivers or software. Some drivers and security tools temporarily block upgrades until a compatible version is installed.
- Insufficient free disk space. Clear space on the system drive and retry.
If none of that helps, the Installation Assistant is the sensible next step for a supported PC.
If the upgrade fails or rolls back
A failed upgrade that returns you to Windows 10 is frustrating but usually recoverable. Work through these in order:
- Note the error code. Windows shows a code on the failure screen. Search Microsoft's support site for that exact code rather than guessing.
- Free up disk space on the system drive and run Disk Cleanup.
- Disconnect unnecessary peripherals — printers, external drives, docks — and retry.
- Update drivers, particularly chipset, storage and graphics, from your PC manufacturer's site.
- Temporarily disable third-party antivirus only if its vendor documents that it blocks upgrades, then re-enable it afterwards.
- Run the Windows Update Troubleshooter from Settings > System > Troubleshoot.
If the machine will not boot normally after a failed attempt, stop and seek help rather than repeatedly forcing restarts. Our Windows troubleshooting guide covers common boot and error scenarios in more depth.
Unsupported PCs: the honest answer
There are workarounds circulating online for installing Windows 11 on unsupported hardware. They exist, but they come with real downsides: Microsoft does not guarantee updates on unsupported configurations, and future feature updates may fail or leave the machine in a worse state. For a home PC used for email and browsing, the risk may be tolerable to some people; for a work machine holding business data, it usually is not.
If your PC fails the compatibility check, the realistic options are to keep it on a supported path for as long as that lasts, or to plan a hardware replacement. A reputable technician can advise which is sensible for your machine and budget.
When to get professional help
Most upgrades go through without drama. Consider hands-on help if:
- PC Health Check reports a failure you do not understand.
- The upgrade fails repeatedly with the same error.
- The PC will not boot after an attempted upgrade.
- You have business-critical data and no verified backup.
- You need the machine working reliably and cannot afford trial and error.
Hire IT Expert provides Windows upgrade and troubleshooting support for homes and businesses in London, including remote and on-site help. If you would rather have the upgrade checked and run properly the first time, get in touch and we can talk through your machine before anything is changed.
