Moving Windows to Another Drive: A Step-by-Step Approach

You can move Windows to a different drive, but the method depends on whether you're cloning or doing a fresh install

Moving Windows to another drive means transferring your operating system from one physical drive to another—usually from an older or smaller drive to a newer or larger one. The two main routes are cloning (copying everything as-is to the new drive) and fresh installation (installing Windows from scratch on the new drive). Cloning is faster if your current setup works well. A fresh install takes longer but gives you a clean system without old files or settings you don't need.

Before you start, back up your important files to an external drive or cloud storage. This protects your data if something goes wrong during the transfer. You'll also need to know which drive is your source (the one Windows is on now) and which is your destination (the new drive where Windows will go).

Key Takeaways

Cloning copies your entire Windows installation to a new drive and is faster, but a fresh install gives you a cleaner system without accumulated files.
You need a cloning tool (like Macrium Reflect Free or AOMEI Backupper Standard) for the cloning method, or Windows installation media for a fresh install.
The destination drive must be at least as large as the data currently on your source drive, and it will be erased during the process.
After moving Windows, you may need to change your boot order in BIOS so your computer starts from the new drive instead of the old one.
If Windows won't start after the move, you can boot from your installation media and use Startup Repair to fix common problems.

Cloning: Copy Everything to the New Drive

Cloning is the faster option if your Windows installation is working well and you want to keep all your programs, settings, and files exactly as they are. You use a cloning tool to copy the entire contents of your source drive to your destination drive, sector by sector. The result is an exact duplicate that will boot and run the same way.

read a free cloning tool like Macrium Reflect Free, AOMEI Backupper Standard, or EaseUS Todo Backup Free. Install it on your current system. Connect your new drive to your computer—either internally if you have an extra slot, or externally via USB. Open the cloning tool and select your source drive (the one Windows is on now) and your destination drive (the new one). The tool will warn you that the destination drive will be erased; confirm that you want to proceed. Start the clone and wait for it to finish—this can take 30 minutes to several hours depending on how much data you have.

Once cloning is done, shut down your computer. If you installed the new drive internally, you can remove the old drive or leave it in place. If you used an external drive, disconnect it. Restart your computer and enter BIOS (usually by pressing Delete, F2, or F12 during startup—check your motherboard manual). Find the boot order settings and move your new drive to the top of the list so your computer starts from it. Save and exit BIOS. Windows should boot normally from the new drive.

Fresh Installation: Start With a Clean Windows

A fresh install means erasing the new drive and installing Windows from the beginning. This takes longer than cloning but removes old files, temporary data, and settings you may not need. You start with a clean system and install only what you actually use.

You'll need Windows installation media. If you have a Windows license key, read the Windows installation tool from Microsoft's website (search "Windows 11 read" or "Windows 10 read" depending on your version). Run the tool on another computer and create a bootable USB drive. If you don't have a license key, you can still install Windows and use it for free with a watermark; you can purchase a key later if you want to remove it.

Connect your new drive to your computer. Insert the USB drive with Windows installation media and restart. Enter BIOS and set the USB drive as the first boot device. Save and exit. Windows Setup will load. When asked where to install Windows, select your new drive. Windows Setup will erase it and install a fresh copy of Windows. This process takes 15 to 30 minutes. After installation completes, your computer will restart and boot into the new Windows installation. You'll need to reinstall your programs and restore your files from your backup.

Preparing Your New Drive Before the Move

Your destination drive must be at least as large as the data currently on your source drive. If your source drive has 250 GB of files and programs, your destination drive should be at least 250 GB. Check how much space you're using: right-click your C: drive in File Explorer, select Properties, and note the "Used space" number.

If your new drive is brand new, it may not show up in Windows or your cloning tool until you initialize it. Restart your computer and enter Disk Management (search "Disk Management" in the Windows search bar). Look for your new drive in the list—it may show as "Unallocated" or "Unknown". Right-click it and select "Initialize Disk". Choose MBR if your current drive uses MBR, or GPT if it uses GPT (you can check this in Disk Management by right-clicking your current drive and selecting Properties). After initialization, your new drive will appear as a usable drive in Windows and in your cloning tool.

Changing Your Boot Order in BIOS

After you move Windows to the new drive, your computer needs to know to start from that drive instead of the old one. This is controlled by the boot order in BIOS, the firmware that runs before Windows loads.

Restart your computer and watch the screen for a message like "Press Delete to enter Setup" or "Press F2 for BIOS". The key varies by motherboard—common ones are Delete, F2, F10, and F12. Press it repeatedly as soon as you see the message. BIOS will open. Look for a section called "Boot", "Boot Order", or "Boot Priority". You'll see a list of drives. Use the arrow keys to highlight your new drive and move it to the top of the list (the exact method varies by BIOS, but you usually press + or - keys or Page Up/Page Down). Save your changes (usually Ctrl+S or by selecting "Save and Exit") and restart. Your computer should now boot from the new drive.

What to Do If Windows Won't Start After the Move

If your computer restarts after the move but Windows doesn't load, or you see an error like "BOOTMGR is missing" or "No bootable device found", the boot order may not be set correctly, or there may be a problem with the boot files on the new drive.

First, restart and enter BIOS again. Confirm that your new drive is listed first in the boot order. If it's not, move it to the top and save. If Windows still won't start, you may need to repair the boot files. Insert your Windows installation USB drive, restart, and boot from it (you may need to press a key like F12 to choose the boot device). On the Windows Setup screen, click "Repair your computer" at the bottom left. Select "Troubleshoot", then "Advanced options", then "Startup Repair". Windows will scan and attempt to fix boot problems automatically. This resolves most startup issues. If Startup Repair doesn't work, you can try a fresh install on the new drive using the same USB media.

Keeping or Removing Your Old Drive

After Windows is running on your new drive, you can keep your old drive connected or remove it. If you keep it, you can use it for storage or backups—just make sure it's not set as the boot drive in BIOS, or your computer may try to start from it instead of the new one.

If you want to erase the old drive and reuse it, you can format it in Windows. Right-click the old drive in File Explorer, select "Format", give it a name, and confirm. This erases all data on it and prepares it for new files. If you're selling or recycling the old drive, use a tool like DBAN (Darik's Boot and Nuke) to securely wipe it so the data can't be recovered. read DBAN, create a bootable USB drive with it, boot from that drive, and follow the prompts to wipe the old drive completely.

Frequently Asked Questions

Do I need to buy a new Windows license if I move to a new drive?

No. Your Windows license is tied to your hardware, not to a specific drive. Moving Windows to a different drive on the same computer doesn't require a new license. If you're moving to a completely different computer, you may need to reactivate Windows or purchase a new license depending on your license type.

Can I clone to a smaller drive?

Only if the smaller drive has enough free space for all your data. If your source drive has 500 GB of files but your destination drive is only 250 GB, cloning will fail. A fresh install on a smaller drive works fine because you can choose to install only what you need.

What if my new drive doesn't show up in my cloning tool?

The drive may not be initialized. Restart your computer, open Disk Management, find the new drive in the list, right-click it, and select "Initialize Disk". Choose MBR or GPT to match your current drive. After initialization, the drive will appear in your cloning tool.

How long does cloning take?

Cloning speed depends on how much data you have and the speed of your drives. Expect 30 minutes to 2 hours for most systems. An external USB drive will be slower than an internal drive. A fresh install typically takes 15 to 30 minutes.

Can I use my old drive as a backup after moving Windows?

Yes. After confirming Windows runs on your new drive, you can format your old drive and use it for storage or backups. Make sure it's not set as the boot drive in BIOS. You can also keep it as-is without formatting if you want to preserve the old Windows installation as a backup.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.