How to Reinstall Windows on Your PC (Clean Install or No Format)

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Need to reinstall Windows on your computer?

I had to reinstall my Windows without losing any data. The system was corrupted and there was no way of retrieving my local disk (C Drive).

However, I needed my other three drives and all the files in them. In this tutorial, I’m going to walk you through how you can reinstall your Windows computer.

Whether you want to clean install Windows or keep your files, this guide is for everyone. I had Windows 10 installed and I had to reinstall it for a system failure which couldn’t be reset. I also tried using automatic repairs but it failed.

Things to check: requirements

Before you can reinstall Windows, you need either a CD drive or a bootable USB drive. I created a bootable drive but I’m going to tell both methods.

  • Windows installation disk
  • A pen drive (USB Drive).
Windows Installation Disk

If you have an installation disk, you don’t have to download the ISO file and create a bootable disk like I had to.

You can just slide the CD-disk in and boot the CD-drive and reinstall Windows.

USD Pen Drive

Here’s how to reinstall Windows without a CD or installation drive.

If you do not have a CD-drive like I don’t. Then you better have a USB drive. Sad enough, I had to borrow one from my cousin since I lost mine.

We’re going to create a bootable USB drive which can help us reinstall the operating system. Very simple, all you need is the ISO file. Just keep reading, you will know.

How to Reinstall Windows on your Computer?

Firstly, keep in mind whether you want to keep everything and just reinstall Windows or you want to clean install. Either way, it’s very simple and easy.

Even if you’re moving from an old version of Windows to a newer version, everything is going to be fine. But I’m not covering the upgrading of OS.

Little Warning: If you’re moving from the 32-bit OS to 64-bit OS, there’s no way of keeping your files. You need to create a backup of those files before you perform the reinstall.

How to use an installation disk?

Open your CD-Drive and put the disk in place. Then, restart your computer and go to the BIOS options.

You have to press F2 or F10 to launch the BIOS settings. For me, it’s F2. This varies with different motherboard manufacturers. Here’s a guide by PCWorld.

bios boot menu, set CD Drive boot menu

But when you see the launch screen, you will see on the bottom the key you need to press to open the boot options or BIOS settings.

Navigate to the Boot Options. Then choose the CD-Drive as the first boot device. This will start the installation instead of starting the current version of Windows.

How to use a USB Drive?

Plug in your USB drive and similarly, launch the boot options and choose the USB drive as the first boot device.

This will start the installation wizard for Windows just like the CD-drive would.

How to Reinstall Windows 7 on PC?

Windows 7 setup, install windows 7, reinstall windows 7

Do you have a Windows 10 installation disk? If no, you need a USB drive. Once you have created a bootable Windows 7 USB drive, you can use that to reinstall Windows.

If you have only one computer at home, ask a friend to help you create the disk. I used my laptop to do the task.

After everything is ready, you need to follow these steps.

When the setup wizard starts, click on Install Now and then choose your preferred language and click “Next“.

You can also customize your Windows 7 using the transformation pack (a reinstall is worth a little customization). Now, let’s get into the steps. 😉

Reinstalling Windows 7

Once you are done with that, just follow the steps to reinstall the OS. I’m dividing things into TWO.

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Method 1: No Format (Keep all your files)

If you do not want to format or lose your files, follow these steps.

When you’re in the installation wizard, choose Upgrade. This will keep all your files and move the C-Drive’s data into “” folder in the new C-Drive installation drive.

This is a straight-cut process. You can find the images below to help you through the installation process.

Once the installation starts, you can sit back and enjoy.

Method 2: Clean Install (Remove everything)

If you want to perform a clean installation of Windows 7, choose Custom. When you’re taken to the partition creation window, select C-Drive and click on “Format”.

If you wish to keep your other drive’s data, you can, or else, just format them as well.

You can create new partitions or delete existing ones in the Partition Manager.

You can also format the primary partition or all the other drives. Depends on if you want to keep any files or perform a clean install of Windows.

You can read below how to delete all drives and create unallocated space to create new partitions of any size. 😛

windows 7 partition creation, windows partition creation, create windows partitions

You can also delete the existing drives to created unallocated or free space which can be used to create drives of your choice.

Follow the same basic installation process shown above. Wait until the installation is finished.

How to Reinstall Windows 8/8.1 on PC?

reinstall Windows 8, windows 8 setup

I have said everything you need to do before installing the operating system on your computer. The same process is for Windows 8 and 8.1 as well.

You just need an installation disk or a bootable USB drive. I’ve already said how you can start the installation wizard.

You can just follow the mini-guide above… 😛

You just have to go the BIOS options and change the first boot device into the USB or CD-drive. Depends on what you choose to use.

Reinstalling Windows 8/8.1

Similar to what you do when you reinstall Windows 7, you do the exact same thing for Windows 8 as well.

You either decide to reinstall without losing your data or perform a fresh new install.

windows 8 custom install, windows 8 clean install, windows 8 upgrade

Method 1: Do not lose any data

Just as in Windows 7 reinstallation process, choose Upgrade and this will keep all your drives safe. Your C-Drive will also be safe in a folder named ““.

Once the installation is done, you’re good to go. This is simple, isn’t? 😛

Method 2: Format everything or C-Drive only

Now, you might want to keep your other files except for the C-Drive. Here’s how to do it.

You choose Custom and when you’re asked to review the partition, select C-Drive as your primary drive to install Windows. But before that, make sure to click on Format after selecting the C-Drive.

You can create new partitions or delete existing ones in the Partition Manager.

You can find a mini-guide below to help you format drives and also free up space for creating new partitions.

windows 7 partition creation, windows partition creation, create windows partitions

If you do that, that’s a clean and fresh installation of Windows, although, your other files will be available, which is kinda useful.

However, if you want a complete format, just feel free to select each drive and keep clicking on Format unless you’re done. You can also delete the drivers to reallocate the space or create more drivers or reduce the number of drivers. That’s up to you.

How to Reinstall Windows 10 on PC?

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I had to reinstall my Windows 10 just some weeks before. Lucky enough, most of my data were safe but I did lose my large meme collection.

Feels bad… 🙁

I just reinstalled the OS and just had to format the C-Drive as I had no backup. I needed my other files, so things went right.

This is the same thing as for Windows 7 and 8. You can read the mini-guide above to know how to start the setup wizard. It’s the same for all Windows versions.

Reinstalling Windows 10

Once you have booted the USB drive or the installation disk, here’s what to do.

You either all your files, format everything or just format the C-Drive (that’s what I did).

You can install Windows 10 from USB or the CD. I prefer using a USB 3.0 Pen Drive which makes the process a lot faster (I think so).

clean install windows 10, reinstall windows 10

Method 1: Keep and don’t lose any data

Simply, choose Upgrade. I know, it’s the same god-damn thing, but Microsoft had made it easier for users.

Good thing. 😉

This will reinstall the Windows 10 and keep all your files, including the C-Drive in a folder named ““.

Once the installation starts, wait for a few minutes, this will take a while, depending on your bootable device (disk or USB).

Method 2: Clean install or remove all files

Just like Windows 8 and 7, you need to choose Custom. Then, you will be asked to check the partition. You have to select C-Drive and click Format.

That will get rid of the current Windows 10, and you can now install the new Windows 10. However, if you wish to delete other files too, feel free to format every drive.

You can also delete the drives and create new drives according to the unallocated space. 😛

How to format Drives or Create New Partitions?

Choosing the Custom option in the setup will let you perform a clean install of Windows. You can format the C-Drive only or everything. That’s up to you. 😉

But how do you create partitions? It’s easy.

where to install windows, windows partition creation

If you want to remove every file in your system, simple, delete all the drives. Select each drive and click on “Delete“. This will create “Unallocated Space” which can be used to create new drives.

Then, click on “New” and set the size of the drive in megabytes. If you have a 1 TB hard drive and you want to create 3 drives, use a calculator and divide the total free space available by three.

That’s how you create new partitions, easy right?

You can also read my guide for setting virtual memory for a faster system.

Note: However, if you want to keep your current partitions but you just want to delete all files, just click on “Format” instead of deleting the drives.

The installation process will start as you choose C-Drive as your primary installation drive. This will take a few minutes, and Windows 10 will be set up for you.

The setup process for Windows 10 simple and easy. If you’re thinking if you need a key, you don’t need one.


This is how you can reinstall any Windows on your PC. I’ll be writing another guide to help you upgrade your OS to a newer version.

The steps for all Windows 10, 8 and 7 are very similar.

You need to use a bootable USB drive you don’t have an installation disk. Put in the disk in your CD-Drive or plug in the USB drive. Then, go to your BIOS settings and select your boot device.

You can then follow the detailed guide above to how to reinstall each operating system. I have shown both methods – clean install and keep all your files.

This is how you can reinstall your OS without losing your data or remove everything. I have broken down things into chunks and simple steps to help you act fast.

Found this guide helpful? Share this on social media to help out your friends. Let me know in the comments if you have any questions or problems. 😀

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