How to Reformat Windows 10

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The viruses, however, are not the only reason one should reformat windows 10 on their PCs. The computer may be running super slow and diagnosing the issue can take up quite some time.

You may also want to sell your laptop without any of your personal data in it. The only option is to format your hard drive and place a new copy of Windows 10. Whatever the reason, knowing how you can go through it can save you loads of cash.

There are basically two major ways you can format your Operating System:

  1. Using a bootable flash drive
  2. Using a bootable Windows 10 DVD

Method 1: Using a Bootable Flash Drive

You can use a USB memory stick to install a clean copy of Windows 10. This can be done using any working USB drive that is above 4GB.

You can still use a 4GB USB drive for formatting your computer with the earlier version of Windows 10 (32 bit only). The other versions, however, are larger in size. They require a bigger storage than the earlier 32 bit version.

This is how you can reformat Windows 10 with a pen drive:

Step 1: Download Power ISO


Power ISO is a compact software for Windows that enables you to write RAW data into flash drives. It converts the drive to become bootable, hence you can use it to boot instead of the hard drive.


You can use the free trial copy to create the bootable USB. You do not need to purchase anything at this point, though you should if you can.

If you already have a copy of Windows 10, skip over to step 3.

Step 2: Download or Prepare a Windows 10 ISO file

Power ISO writes image files with boot info to the pen drives. You cannot, therefore, write individual files the same way.

If you do not have any copy of Windows 10, you could get a genuine copy of the OS from Microsoft’s Website:

DVD option:

If you have a DVD, you can use Power ISO to create an archive for its contents. Insert the DVD and open it to show the files.

Press ctrl+A to highlight everything in the DVD. You now can drag and drop the contents into PowerISO. Alternatively, you can just press ctrl+C to copy the highlighted items and paste into Power ISO by pressing ctrl+V while its the active window.

PowerISO 2

After all that is over, go to the Action tab and scroll to “boot” to add boot information. Under boot, click on ‘add boot information’ and browse through the DVD.

The folder you are looking for is a boot. Open it and search for etfsboot. You may need to change the view to ‘all files”.”‘. After you have selected the file, the image file should read bootable now.

Create bootable Window ISO from USB

Save the image file after it has finished pasting the contents by pressing ctrl+S. It will prompt you to choose the extension type the image will be.

You can choose any of the image extensions available. it is advisable, however, that you save it as an ISO image file.


When the file is saved, you need to return to Power ISO and click on the tools tab. Under the tools tab, click on ‘create bootable USB drive…’. You may be prompted to start power ISO as an admin if you did not do it earlier.

A new window will launch, giving you options for the bootable flash. You need to choose the ISO file you created earlier and the pen drive that you are supposed to use.

Create Bootable Flash Drive Windows 10

You should be careful with this if you have external hard drives. Make sure that you choose your pen drive as this will format everything in it to write the OS.

Click on start and wait for the process to complete. You should not remove or disturb the pen drive during this process as your device may be damaged.

It should take your computer a few minutes to finish copying the files to your flash disk. You can reboot your computer afterwards.

Step 3: Boot to The Boot Options

As the computer reboots, you need to press either esc, f9 or f12 while it’s on the boot screen. These buttons take you to the boot options of the computer where you get to choose which drive the computer should boot to.

Boot Menu

Please note that you are not supposed to press all the buttons at once. You should try each one of them and see which one leads to the boot menu (some boot screens show the options). Select your pen drive and wait for the computer to finish booting.

Step 4: Start the Windows 10 installer

The first prompt you get is to choose your language. Select the preferred language and click on next. You will then get a window with an ‘install now’ button which you obviously should click on.

Windows 10 Installer

Next, you need to choose which type of installation you need to perform. If you have a previously installed window that contains important files and documents, you should choose the first option. This way, you get to keep your files and still have a fresh Windows 10.

Windows 10 Installer 2
This, however, will not work if you lack space in the partition. You need at least 10GB free for the system files to be copied. If space is available, click on next and begin the installation.

In the case of a viral infection, your files are already lost and corrupted. You should select the second option which will take you to the partition manager. If you decided to keep your files, ignore the 5th step:

Step 5: Select and format your partition

Choose the partition that you are going to install windows to. Normally, a large hard drive is divided into two or more so that a person can store some data where they can be recovered in case the computer is formatted.

Windows 10 Installer 3

You should see three partitions reading:

  • System Reserve
  • Primary 1 (:C)
  • Primary 2+ (:D, :E, :F…)

You need to delete the first two partitions. You should delete the System Reserve so that details of the previous OS is deleted. The Partition will otherwise be shown on your list of partitions, which can be annoying.

Afterwards, click on the Unallocated Space and select new. Do not try to split the partition into the two that you deleted. The system will do it for you. Just click on new and finish it off without changing the size.

Windows 10 Installer 4

Click on next and let the installer copy the Windows 10 files to your computer.

You have to wait for the installation to complete. After that, the computer will reboot to your new copy of Windows 10.

Method 2: Reformat using a Bootable DVD

You can acquire a Windows 10 DVD in the stores or the one downloaded from the Microsoft site to create a DVD.

The ISO file is already bootable and you just need to burn it onto an empty DVD. You can use any image software to complete to complete the process, preferably Power ISO.


The process is just the same as reformatting with the flash drive. Insert your DVD into your drive and refer to step 3 under method one. Follow the procedure from step 3 up to the last one and you should have a working copy of windows.

Windows 10 Installer 5

1 thought on “How to Reformat Windows 10”

  1. You need to provide a little bit more instructions about this program, because it did not respond to my computer to finish it’s work.


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