Installing Windows from a USB Drive Without Formatting the Hard Disk

Installing Windows from a USB drive is a convenient and efficient way to upgrade or repair your existing installation without losing your data. This guide provides a detailed step-by-step process to achieve this goal using a USB drive and ensuring minimal disruption to your system. Whether you are replacing an old operating system or doing an in-place upgrade, this method ensures your data remains intact.

Prerequisites

A USB drive with at least 8 GB of storage The Windows installation ISO file from the official Microsoft website Rufus or Windows Media Creation Tool for creating a bootable USB drive

Step-by-Step Guide

Create a Bootable USB Drive

The first step is to create a bootable USB drive using either Rufus or the Windows Media Creation Tool.

Using Rufus

Download and open Rufus Insert your USB drive Select the USB drive in Rufus Choose the Windows ISO file you downloaded Select the partition scheme MBR for BIOS or GPT for UEFI Click Start

Using Windows Media Creation Tool

Download the tool from the Microsoft website Open the tool and select the system edition of Windows desired

Follow the on-screen instructions to finalize the creation of the bootable USB drive.

Boot from the USB Drive

Now that you have a bootable USB drive, follow these steps to boot from it.

Insert the bootable USB drive into the computer Restart the computer and enter the BIOS/UEFI setup (usually by pressing F2, F12, Delete, or Esc during boot) Change the boot order to prioritize the USB drive Save changes and exit

When the boot menu appears, select the USB drive as the boot device.

Start the Windows Installation

Once Windows starts from the USB drive, follow these further instructions.

Select your language, time zone, and keyboard preferences Click Next Under Install now, click Install Windows from an existing copy of Windows Select the installation source (type in your serial number if prompted) Click Next and proceed with the installation

Make sure to select Install Windows keeping files to preserve your existing data and applications.

Important Notes

Backup Your Data: Always back up important data before performing an installation, even if you plan to keep files. Windows Activation: Ensure that you have a valid product key if required for activation after installation. Compatibility: Check system requirements for the version of Windows you are installing to avoid compatibility issues.

By following these steps, you can install Windows from a USB drive without formatting your hard disk and while keeping your existing files and applications intact.

Note that if your USB drive is in a raw state (i.e., not formatted), it does not have a file system. Therefore, the OS cannot read/write on it. It must be formatted, typically on FAT32, because it is compatible with many file systems. After formatting, Windows will format it to NTFS and install its system files. If you want a portable version of Windows, consider using Win2Go, which can clone an installed Windows setup with drivers and programs.