How to download and and carry out a clean install of Windows 10

We show you how to install the Windows 10 operating system from scratch

Windows 10 is the latest version of Microsoft’s flagship operating system, following on from Windows 7, Windows 8 and Windows 8.1, and was released as a free upgrade to all existing customers.

For the first time in Windows’ illustrious history, the new OS is available exclusively via online download, which means there’s no CD, no floppy disk and no USB key. This can make installation a tricky prospect.

Thankfully, there are a number of ways to migrate old systems to Windows 10. Some methods make the switch while preserving all the computers’ files and settings, but if you want to carry out a clean install, some methods will revert the PC back to its original factory state.

If they decide that they don’t like Windows 10 after all, users can freely roll back to their previous OS at any point in the first 30 days.

If you haven't yet updated your PC to Windows 10, you've sadly missed your chance to take advantage of the free upgrade, which expired on 29 July 2016.

This means that you'll have to stump up the cash for a Windows 10 license. Windows 10 Home is available from the Microsoft Store for £99.99 inc VAT, or you can pick up Windows 10 Pro for £189.99 inc VAT.

You can choose to either download the update directly, or Microsoft can sent you a Windows 10 USB which you can use to install it.

While installing in place with older versions of Windows was a scary enough process that we wouldn’t have recommended it, it’s a far easier thing with Windows 10. The first way is the most straightforward but will take longer. If you’re unsure about using Microsoft’s latest and greatest, go for the latter method instead which is faster but involves a little more work.

Please remember that if you have a retail copy of Windows 7 or 8/8.1, you can transfer your licence to a new computer by first installing Windows 7/8.1 on another computer and then upgrade to Windows 10 using one of the methods below.

Permanently disable upgrade notifications

While Windows 10 is a great operating system, Microsoft has come under no small amount of fire for its bullish tactics in promoting it. Users have complained that Microsoft is foisting the update on users, up to the point of automatically downloading it onto their PCs.

Not only are the persistent prompts annoying, they also have a tendency to be very sneaky about hiding the option to defer installation. For example, recent updates have reportedly started treating shutting the app via the ‘X’ icon in the top right as acceptance of the update.

Thankfully, now that the free upgrade offer has expired, there's no reason for Microsoft to nag you, and the company has promised that the update pop-ups are now a thing of the past.

Method One: Windows 10 reservation tool

1. While we didn’t have any problems during our installation, it’s always a good idea to backup your computer prior to installing any new software - particularly something as important as a new operating system. Should anything go wrong, at least, you’ll still have duplicates of all your files.

2. In advance of installing Windows 10, you’ll need to ensure that all the latest updates available for your existing installation of Windows (7 SP1 or 8.1) are installed. Go to Control Panel\All Control Panel Items\Windows Update (Windows 7) or Control Panel\System and Security\Windows Update and follow the on-screen prompts to install all available Important updates.

3. Once these updates are installed, you’ll see a tiny Windows icon in your System Tray. Click it and follow the on-screen prompts - a wizard will check your computer for compatibility and ‘reserve’ your copy of Windows 10 in Microsoft’s staggered worldwide download queue.

4. When your reserved copy of Windows is ready, you’ll see a dialog box prompting you to download the installer. Accept and the long wait begins. The exact size of the installer will vary depending on your existing setup, but it will be in the region of at least 2.5GB.

5. Once the installer has downloaded, another dialog box will prompt you to finally start the installation itself (hooray!) either straight away or at a later time. The lengthy download will be followed by an equally lengthy ‘preparing for installation’ phase, so scheduling for installation will be a good idea. Follow the on-screen prompts to start installation - it’ll be another lengthy process, but it’ll be worth it.

Method Two: Windows 10 Media Creation Tool

3. Find out whether you’re running a 32-bit or 64-bit version of Windows. Under Windows 7, you can find this information in Control Panel\All Control Panel Items\System. Under Windows 8.1, it’ll be in Control Panel\System and Security\System

4. Download the Windows 10 Media Creation Tool. Although intended primarily for creating a Windows installation DVD or USB stick, you can also use it to upgrade Windows in place. Make sure you download the right version for your PC - either the 32-bit version or the 64-bit version.

5. Once the Tool has downloaded, run it and follow the on-screen prompts to download and install Windows 10. Download and installation can take a long time, so don’t do it if you’re in a hurry. The exact size of the installer will vary depending on your existing setup, but it will be in the region of at least 2.5GB.

Method Three: Performing a clean install of Windows 10

The upgrade process in Windows 10 takes old files, settings, and programs from a previous system to a new one. You can, however, refresh your computer completely by carrying out a clean install. However, the activation process can be trickier.

A clean install can come in handy if you want to dodge the ton of bloatware that manufacturers install. It is also necessary when you have replaced a hard drive.

By far the easiest way to do a clean install is to use Windows 10’s Reset function. This differs from the Windows 8 Reset function as that feature used a recovery image from manufacturers that was customised for their software. Sure, that would include the specific drivers from them, but this also included bloatware and in some cases (*cough* Lenovo) undesirable software such as Superfish.

Windows 10 purports to have a system in place that rebuilds Windows without the need for a separate recovery image. This cleans up the system and keeps the latest files. This also means that you don’t have to run Windows Update directly after a reset.

Microsoft claims this resetting brings “Windows devices back to a pristine state” with only Windows files installed.

To reset your Windows 10 PC, open the Settings app, choose Update & security, choose Recovery, and click the “Get started” button under Reset this PC. Choose “Remove everything.” This will wipe all your files, so be sure you have backups.

And don't forget!

Most people unaware that after installing Windows 10, the previous version of the OS is still lingering in the background taking up valuable space. When you upgraded, your old version of Windows didn’t just disappear into thin air. Oh no, it’s still there in the back of your system going by the name of ‘windows.old’ and taking up disk space.

This is because Microsoft doesn't force you to update your hardware and never look back, it keeps a hold of the important files that made up your previous OS in the C:/ drive in case you don’t like Windows 10 and decide to revert back to your previous version.

To delete it forever, hit the Windows Start button and start typing “cleanup” to automatically search your system. A ‘Disk Cleanup’ app should appear before your eyes in the search criteria field. Click on this to open the app.

A drive selection box will pop up. Select the drive your OS is installed on. The default drive should show first, this is usually C:/ drive. Once you’re confident this is your main drive where your OS is installed, select OK. Windows will scan your system for a few moments, then a box will pop up.

Now, two things could happen at this point. You could be presented with a list of files to delete right away, one of which is “Previous Windows Installation(s)”, or if that option is not visible, you will need to select the “Clean up system files” option on the bottom left.

Windows will do some more calculations and give you another a very similar looking box, this time with the option to delete ‘previous windows installation(s). You might have to scroll down to find it, but it should be taking up a sizeable bit of drive space, in our case, almost 5GB. Tick this option and click OK. In the separate message box that appears asking if you’re certain you want to send this, click Delete Files, and you’re done.

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