How to Move Windows to a Different Drive

You can move Windows to another drive, but the method depends on whether you want to clone your entire system or do a fresh install

Moving Windows to a different drive is possible, but it is not the same as copying files. Windows is tightly bound to your hardware, and moving it requires either cloning your existing installation (which copies everything as-is) or performing a fresh install (which starts over). Cloning is faster if your current setup works well. A fresh install is cleaner but takes longer and means reinstalling your programs.

The drive you are moving to must be large enough to hold Windows plus your files — Windows 11 needs at least 64 GB of free space, though 128 GB is safer. If you are moving to an external drive, the process is the same, but Windows will run slower because external drives have slower data transfer speeds than internal ones.

Key Takeaways

Cloning copies your entire Windows installation to a new drive and is the fastest method, but requires cloning software and a way to connect both drives to your computer at the same time.
A fresh Windows install is cleaner and avoids carrying over old files or settings, but requires a Windows installation media and a product key if you want to activate Windows afterward.
Before moving Windows, back up your important files to an external drive or cloud storage in case something goes wrong during the transfer.
After moving Windows to a new drive, you may need to change your boot order in BIOS so your computer starts from the new drive instead of the old one.
If you clone Windows to a smaller drive, the clone will fail — the destination drive must be equal to or larger than the drive you are copying from.

Cloning your existing Windows installation to a new drive

Cloning is the fastest way to move Windows because it copies your entire drive — operating system, programs, files, and settings — to the new drive. You end up with an exact duplicate of your old drive on the new one. The downside is that you need cloning software (some options are free, others cost money) and you need both drives connected to your computer at the same time.

To clone, you will need a cloning tool. Free options include Macrium Reflect Free, EaseUS Todo Backup Free, and Aomei Backupper Standard. Paid options like Acronis True Image offer more features but are not necessary for a basic clone. Download the software on your current computer, install it, and then connect your new drive to your computer using a USB adapter or by opening your case and plugging it in directly.

Open the cloning software and select your current drive as the source and the new drive as the destination. The software will warn you that everything on the destination drive will be erased — this is normal. Start the clone and wait. Depending on how much data you have, this can take anywhere from 30 minutes to several hours. Do not interrupt the process or turn off your computer.

Once the clone is complete, shut down your computer, remove the old drive (or leave it disconnected), and restart. You may need to enter BIOS (usually by pressing Delete, F2, or F12 during startup) and change the boot order so your computer starts from the new drive. If Windows starts normally, the clone worked. If you see an error, restart and check BIOS again to make sure the new drive is set as the first boot device.

Doing a fresh Windows install on a new drive

A fresh install means erasing the new drive and installing Windows from scratch. This takes longer than cloning but gives you a clean system without old files, programs, or settings you no longer need. You will need a Windows installation media (a USB drive or DVD with Windows on it) and your Windows product key.

To create installation media, go to Microsoft's Windows download page on another computer and download the Windows installation tool. Plug in a USB drive with at least 8 GB of space, run the tool, and follow the prompts to create bootable media. This USB drive will contain everything needed to install Windows.

Plug the USB drive into your computer, connect your new drive, and restart. Enter BIOS and set the USB drive as the first boot device. Save and exit BIOS. Windows setup will start. When asked where to install Windows, select your new drive and let the installer format it. Follow the on-screen prompts to complete the install. This usually takes 20 to 40 minutes.

After installation, Windows will ask for your product key. If you are moving from an older version of Windows on the same computer, your key may activate automatically. If not, you can enter your key during setup or skip it and enter it later in Settings. Once Windows is installed and activated, you can reconnect your old drive if you want to copy files from it, or leave it disconnected and use it as backup storage.

Preparing your computer and backing up your data

Before you move Windows, back up your important files. Even though cloning and fresh installs are usually reliable, things can go wrong — a power failure during the process, a bad sector on the new drive, or a mistake in BIOS settings. A backup means you can recover your files even if the transfer fails.

Use an external hard drive, USB drive, or cloud storage like OneDrive, Google Drive, or Dropbox. Copy your Documents, Pictures, Downloads, and Desktop folders, plus any other folders that contain files you cannot afford to lose. This should take 30 minutes to a few hours depending on how much data you have.

Also write down your Windows product key before you start. You can find it in Settings by going to System > About and looking for "Windows specifications" — it will show whether Windows is activated. If you are moving to a new computer, you will need this key to activate Windows on the new machine. If you are moving to a new drive in the same computer, activation usually happens automatically.

Changing your boot order in BIOS after the transfer

After you move Windows to a new drive, your computer may not start from the new drive automatically. BIOS (the firmware that runs before Windows starts) has a boot order — a list of drives it checks in sequence to find Windows. If your old drive is still listed first, your computer will try to start from it instead of the new one.

To change the boot order, restart your computer and enter BIOS. The key to press varies by manufacturer — common ones are Delete, F2, F10, or F12. You will see a message on the startup screen telling you which key to press. Once in BIOS, look for a section called "Boot Order", "Boot Sequence", or "Boot Priority". Move your new drive to the top of the list and save the changes. Your computer will restart and should now boot from the new drive.

If you are not comfortable entering BIOS, you can also hold down a boot menu key (often F12 or Esc) during startup to see a temporary list of drives. Select your new drive from this menu and Windows will start from it. This does not permanently change the boot order, so you will need to do it each time you restart unless you change BIOS.

Troubleshooting common problems after moving Windows

If Windows does not start after you move it, the most common cause is the boot order. Restart and check BIOS to make sure the new drive is listed first. If it is and Windows still will not start, try the boot menu key instead — sometimes BIOS changes do not take effect immediately.

If you cloned the drive and Windows starts but runs slowly or behaves strangely, the clone may be incomplete or corrupted. Restart the clone process, making sure both drives are fully connected and the cloning software shows no errors. If the problem persists, try a fresh install instead.

If you see a "Windows could not start" or "BOOTMGR is missing" error, Windows cannot find its boot files on the new drive. This usually means the clone failed or the new drive was not properly formatted before the fresh install. Try the process again, and make sure the new drive shows up in BIOS before you start.

If you moved Windows to an external drive and it starts but runs very slowly, this is normal — external drives are much slower than internal ones. If you need better performance, move Windows to an internal drive instead. External drives work for temporary use or backup, but are not practical for everyday use.

Keeping your old drive as backup storage

After you successfully move Windows to the new drive, you can repurpose your old drive. The safest option is to keep it as backup storage — plug it in occasionally and copy important files to it. This gives you a second copy of your data in case the new drive fails.

To use the old drive for storage, connect it to your computer and open File Explorer. If it shows up but is empty or unformatted, right-click it and select "Format". Choose NTFS as the file system (the default for Windows) and give it a name. Once formatted, you can copy files to it like any other drive.

Do not delete the old drive immediately after moving Windows. Wait a week or two and make sure the new drive is working reliably. Once you are confident everything is working, you can erase the old drive and use it for storage, or keep it as a backup in case you need to recover files.

Frequently Asked Questions

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

No. Moving Windows to a different drive in the same computer does not require a new license — Windows stays activated. If you are moving to a completely different computer, you may need a new license depending on your version of Windows and Microsoft's licensing terms. Contact Microsoft support if you are unsure.

Can I move Windows to an external drive and use it on different computers?

Technically yes, but it is not practical. Windows is tied to your hardware, so moving an external drive with Windows on it to a different computer will likely cause activation errors or driver problems. External drives are also much slower than internal ones. Use external drives for backup and storage, not for running Windows.

What if my new drive is smaller than my old drive?

Cloning will fail if the destination drive is smaller than the source drive, because there is not enough space to copy everything. You can do a fresh install on a smaller drive, but you will need to delete files from your old drive first to make room. Alternatively, buy a drive that is at least as large as your current one.

How long does it take to move Windows to a new drive?

Cloning usually takes 30 minutes to a few hours depending on how much data you have. A fresh install typically takes 20 to 40 minutes for the installation itself, plus time to reinstall programs and copy files afterward. The total time for a fresh install can be several hours if you have many programs to reinstall.

Will moving Windows delete my files and programs?

Cloning copies everything, so your files and programs move with Windows. A fresh install erases the new drive and installs only Windows, so you will need to reinstall programs and copy files afterward. Your old drive remains unchanged in both cases, so you can always recover files from it if needed.

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.