How to clean install Windows 10 or upgrade from a previous version

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How to clean install Windows 10 or upgrade from a previous version

Finally biting the bullet and upgrading to Windows 10? Or do you want to give your Windows 10 system a refresh with a clean install? We show you how.

For the first time in Windows’ history, Microsoft’s operating system is available exclusively via online download, which means there’s no CD or floppy disk. While this may seem somewhat daunting, Microsoft has in fact made it easier to install Windows 10. However, choosing the best installation method for your needs is sometimes not so obvious – and there are traps for the unwary, as well shortcuts for those in the know.

Here we’ll explain the best ways to install Windows 10 to allow you to preserve all the computers’ files and settings for an easier transition, or perform a clean install to maximise your system’s performance.

We’ll also show you how to do a clean install the easy way (if you already have Windows 10 installed) and, if you don’t like the new OS, uninstall Windows 10.

Back up!

But no matter why or how you’re installing Windows 10, make sure you put aside plenty of time and remember to back up your important files, using Windows’ backup, any other backup tool, an online syncing service such as Dropbox, or other methods that we’ve explained previously . Don’t forget to backup Outlook and other files that might not be in the Documents (or My Documents) or other obvious folders.

In addition, it could be worth using a third-party tool such as EaseUS Todo Backup Free to make an image of your computer. Although Microsoft provides a way to revert to the previous version of Windows in the first 10 days after installing the new OS, a backup image is additional protection, allowing you to roll back your PC to exactly the way it was (including all your files) before you installed Windows 10.

Installing a new operating system is a big change, with potential for things to go badly wrong, so don’t be tempted to skip the backup step.

Upgrading from a previous version

If you haven't yet updated your PC to Windows 10, you've sadly missed your chance to take advantage of the free upgrade. You'll have to stump up $179 for a Windows 10 Home licence or $299 for Windows 10 Pro the Microsoft Store.

You can choose to either download the update directly, or Microsoft can send you a Windows 10 USB which you can use to install it, although at the time of writing the latter option was “out of stock”. However, that’s not a huge problem, because you can easily create your own Windows 10 installation USB key as we’ll see later.

Remember, 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 a computer and then upgrade to Windows 10.

Next: how to install Windows 10

Installing Windows 10 using the Media Creation Tool

Unless you’ve purchased Windows 10 on a USB stick, the best way of upgrading to the new OS from older version is to use the Windows 10 Media Creation Tool. You’ll need to have purchased a Windows 10 licence first.

First, as we explained previously, it’s vital to backup. Then you’re good to go:

1. 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.

2. 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

3. Download the Windows 10 Media Creation Tool. Make sure you download the right version for your PC – either the 32-bit version or the 64-bit version.

4. Once the tool has downloaded, run it and follow the on-screen prompts to download and start the installation routine.

5. When you get to the ‘What do you want to do?’ page, you can choose to either ‘Upgrade this PC now’ or ‘Create installation media for another PC’. The former is the simplest option and you just follow the prompts to install Windows 10 on that PC. The entire download and installation process can take a fair while, 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.

Installing from an installation DVD or USB

The second option on the ‘What do you want to do?’ page allows you to create a Windows installation DVD or USB stick. While this is an extra step initially, it will save you from having to download Windows for future installations.

An installation DVD can be created by right-clicking on the downloaded .ISO file and burning it to the blank disc. The USB stick must be blank and hold at least 5GB of space.

Once you’ve created either an installation DVD or USB key, just insert it into the computer, restart the PC and press any key during the boot process to start up from the USB drive or the DVD.

If this doesn’t work, you’ll probably need to open your computer’s boot menu and change the boot order in your PC's BIOS or UEFI settings, so that your PC boots from the DVD or USB key first. See your computer’s documentation or website for the key combination that opens the boot menu.

Then, when the disc or drive boots, just follow Windows’ setup instructions.

During this process you’ll be asked: “Which type of installation do you want?” Choose the Upgrade option if you want the more straight-forward way of keeping your files, Windows settings and applications.

Alternatively, choose the Custom option if you want to do a clean install. This will then give you the option of installing Windows on an existing hard disk partition, or creating a new one.

However, if you already have Windows 10 installed and all you want to do is a clean install, there is an easier way – using the Reset function as we’ll see later.

Removing the remnants of the previous version

Many 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.

We advise keeping it for the full 10 days in case you want to roll back to a previous Windows version, but if you’re running out of disk space and you do want to delete the old files 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.

Next: clean installing Windows 10 the easy way

Reset: clean install Windows 10 the easy way

The normal 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 offers a system that rebuilds the operating system without the need for a separate recovery image, cleaning up the OS but keeping the latest files – so you don’t have to run Windows Update directly after a reset.

Microsoft says 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.

Next: how to uninstall Windows 10

How to uninstall Windows 10

With Windows 10, Microsoft has made some big changes to the way its operating system works, and it's managed to win over a lot of people.

However, it's not been a hit with everyone. Some don't like the new Start menu, there have been reports of compatibility issues, and others just aren't comfortable with it. If you're one of the people that wish they hadn't upgraded, fear not - you can still go back to your old version of Windows.

Be warned, though – you 'll need to act fast. When your PC upgrades to Windows 10, the old operating system is kept on the hard drive for around a month; after the Anniversary Update, that falls to just 10 days. This means that you haven’t got long to decide whether or not you like the new OS.

Rolling back

Microsoft has built a feature into Windows 10 allowing users to roll back to their previous Windows version, but it's only available for the first 10 days after you install the new OS. It's still possible to go back to an older version after this period elapses, but it's more difficult and time-consuming.

Before you do this, it is a good idea to make sure all data is backed up using either an external hard drive or a cloud-based backup service. You may also want to ensure your old Windows 7 or Windows 8 product key is to hand.

To roll back to your previous version of the OS, go to the Start menu and choose 'Settings', then ‘Update & security’. Choose 'Recovery' in the left-hand panel and, on the right, find ‘Go back to Windows 8.1' or 'Go back to Windows 7'. Click the ‘Get started’ button below that and follow instructions.

Once you have gone back to the old version of Windows, older programs may need to be installed. 

Of course, this will only work if you still have the Windows.old folder (C:\Windows.old). If you can’t find it or you have deleted it, then you are out of luck.

A clean install

A complete reinstall may be your only option if the rollback method described above is no longer available.

This can also have the effect of removing tons of bloatware that have clogged up your operating system, slowing it down.

A clean install is different from the Reset you PC option in Windows 8 and above. This can often re-install junkware that came from the manufacturer with the laptop. 

This uses just the Windows media (CD or USB) and nothing else and should result in a faster PC as well. It is also a way of dealing with any malware-infected machines or those that have been riddled with ransomware and had data encrypted.

To perform a clean install, insert the Windows DVD into the disc drive or insert a USB containing the Windows installation media into a free USB port. Then turn on the computer (or restart it).                                                      

Look for Press any key to boot from CD or DVD or Press any key to boot from an external device. Pressing a key will force the computer to boot from either the Windows DVD or a flash drive with the Windows 8 installation files on it.

If you can’t find your old disc, as long as you have the product keys, you can download Windows installation media and burn the ISO file to a disc or copy it to a USB drive using Microsoft’s Windows USB/DVD download tool

On a Windows 7 PC, look for a “certificate of authenticity” sticker with a key on it. It is normally on the underside of a laptop or at the back of a desktop PC. For Windows 8 PCs, the key can be embedded in your computer’s firmware. This means Windows 8.1 will automatically detect it and allow reinstallation of Windows 8.1 without even asking for a key. 

Using third-party backup software

If you managed to make an image of your computer prior to upgrading to Windows 10, you can use third-party software to re-install that image onto your computer and get back to a previous version of Windows.

Tools such as EaseUS Todo Backup Free can do this. To create an image, plug in an external drive, run Todo Backup and click System Backup or Disk/Partition Backup

You can use the default settings on this and once the backup is underway, the application can be minimised while performing its task. To create recovery media, click on the Tools icon and select Create Emergency Disk. There are several choices and the best is ‘Create WinPE emergency disk’ and USB. Insert a memory stick with a capacity of at least 1GB.

The USB drive can be used to start the PC. Just press a function key while the machine starts up to boot from USB and this will run the restore software automatically so you can restore the PC. 

Uninstalling via a factory restore

If you find yourself after the rollback time limit with no going back to an old version of Windows, help may still be at hand for some users. On many PCs and laptops, there is a hidden partition on the hard disc that has a copy of the original Windows, programs, drivers and settings, which were on your PC when you brought it back from the shops. With any luck, Windows 10 will have ignored this and left it intact. 

To access it, when booting up look for messages such as “Press F11 for Recovery Options”. Whatever key the PC wants you to press, press that and with any luck, you should get a menu that has options to restore factory settings. 

A restore will very likely wipe the entire C drive, so back up any important data before you do this. You will also have to install a ton of Windows update post-installation as well as any drivers and software for hardware you have installed yourself.

What if my PC only came with Windows 10? 

If you bought a new PC running Window 10 and you want to uninstall this and put an older version on, things get a little trickier. The legitimate way of having an older copy of Windows on this is to buy a Windows 7 or 8.1 licence and install it from scratch, entering the product key you bought during installation.

This feature includes articles originally published in IT Pro on how to install and uninstall Windows 10.

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Copyright © ITPro, Dennis Publishing

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