How to Change Primary Hard Drive in Windows 10, 8, 7 and Windows 11?

If you want to change primary hard drive in Windows 10, 8,7, and Windows 11 or make the second hard drive as the startup drive, read this article, then you will know how to change boot hard drive in Windows PC with detailed steps.


By Emily / Updated on June 11, 2024

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Why change primary hard drive in Windows 10?

“I have a laptop with SSD 32 GB - C drive and I later added additional SSD with 240 GB D drive. Windows was installed on C drive. Currently, all new programs are getting installed by default on C drive. I do not have the option to choose where they will be installed. So, I want to chang the local disk from C to D and installed Windows 10 on D drive. How can I change the primary drive and make the second bigger SSD drive as the primary one? Anyone can help? Thank you, ”

From the above user case, we can know that users might want to replace a smaller older hard drive with a bigger new hard drive when the current hard drive is almost full of system files, programs and other personal files. Besides that, another main reason for changing startup drive is to upgrade a slow hard disk to a faster SSD drive when your Windows OS is now installed on a mechanical traditional hard disk drive that tends to slow in accessing data.

What to do before changing primary hard drive

Before you change the primary hard drive, there are some preparations you need to know:

1. Make a backup of the data on the old drive
To avoid accidental data loss, It is advisable to establish a data backup on the old drive to mitigate the risk. This can be accomplished using the Windows built-in backup tools or third-party backup tools. 

2. Choose a proper hard disk
You need to select a suitable hard disk to replace old disk. An HDD should be your primary choice if you are interested in a large capacity at a low price, while an SSD should be your first choice if you prefer high performance. Further, it is imperative to verify that the disc interface of the new drive is compatible with your personal computer when selecting it. Lastly, evaluating your new drive's storage capacity is important. In general, 500G is sufficient for installing the operating system, storing data, and future updates.

3. Set your disk for your computer
If you are changing primary hard drive from MBR to GPT, you have to ensure your motherboard supports UEFI or EFI boot mode because it is necessary to upgrade Legacy to UEFI for a smooth boot.

4. Check hardware
Make sure you connect the destination disk you want to make the new boot hard drive to your PC and ensure it is detected. Otherwise, other hardware may cause your PC boot to fail.

How to change startup hard drive in Windows 11/10/8/7

To set primary hard drive in Windows 10, or make the second hard drive as the primary drive, you can fresh or clean install Windows OS on the new SSD/HDD, or install Windows on a second drive. Or you can change the primary hard drive by migrating OS to another disk. Those are two practical methods and you can follow the tutorials to get the complete info.

Method 1. Change boot disk by fresh or clean installation (complex)

To clean install the Windows on another disk and make it bootable, you need to prepare an empty USB (8GB min), download Windows Media Creation Tool and Windows product key (activate after installation).

Before proceeding: check whether the partition stlyes of the target and source primary drive are same. If not, you had better first convert the destination disk to MBR or GPT in case that you meet the errors: “Windows cannot be installed to this disk. The selected disk is of the GPT partition style” or “The selected disk has an MBR partition table”.

Step 1. Download Windows Media Creation Tool, launch it and choose “Create installation media (USB flash drive, DVD, or ISO file) for another PC” and click “Next”.

Create Installation Media

Step 2. Select the empty USB as the target drive, and follow the onscreen instructions to create a bootable USB drive for installation.

Choose USB Drive

Step 3. Then remove the old system disk, insert the new disk you want to make as new primary drive and the bootable USB to your computer, reboot it, enter BIOS, change boot priority and boot computer from the installation media.

Step 4. Once the PC boots from the USB drive, Windows 10 will automatically enter setup mode. Setup preferences, and then click on “Next” > “Install now”.

Windows 10 Setup

Step 5. Input the license key, or skip it and activate it after Windows install completes.

Step 6. In the “Where do you want to install Windows” screen, click on “Custom: install Windows only (advanced).” and choose your new drive. Click “Next” to install OS on the target disk.

Step 7. After the installation, restart your PC, enter BIOS to change the boot drive by setting SSD as the OS drive.

Change Boot Order

At last, you can shut down your computer, remove the installation USB drive, reinsert the old hard drive to your computer and use it as a data drive.

Method 2. Change startup hard drive by OS migration (straightforward)

If you want to change primary hard drive in Windows 11/10/8/7 without reinstalling system, you can make use of a professional partition manager that supports to migrate system another HDD or SSD. Then the “Migrate OS to SSD Wizard” of AOMEI Partition Assistant Professional can meet your requirements best. It enables you to transfer system between HDD and SSD no matter whether they are of the same partition style or not. And you don't need to worry that you cannot boot Windows from the new disk afterward. 

Free Download Win 11/10/8.1/8/7
Secure Download

Step 1.Install and launch AOMEI Partition Assistant Professional. Click "Clone" > “Migrate OS”.

Migrate OS to SSD

Step 2. Choose an unallocated space on your destination disk and click on “Next”. If there is not unallocated space, you can tick “I want to delete all partitions on this disk to migrate system to the disk”. If you have to choose this option, please back up all necessary data on the disk beforehand.

Select Space

Step 3. You can specify the size or the location of the new system partition on the new disk.

Resize Partition

Step 4. Then comes a boot note. Read it carefully if necessary and click on “Finish”.


Step 5. Click on “Apply” to commit the pending OS migration operation.


Wait for the process to complete, and then you can restart your computer, enter BIOS setup, and change the boot order to boot the computer from the new startup disk.

You may also want to know...

If you desire to move everything on the current boot disk to another disk and make it new system hard drive, please try the “Clone Disk” feature, which will clone one hard drive to another hard drive and make it bootable.

Disk Copy Wizard

The above content focuses on how to make a second hard drive primary in Windows 11/10/8/7. Some users are searching for a way to change the local disk C to D, namely, moving OS from C drive to D drive so as to make D partition as the boot partition. For this purpose, you can apply the “Clone Partition” feature to clone C partition to D partition (note: this requires you to delete D partition to make it an unallocated space first of all).

Copy Partition


How to change primary hard drive in Windows 10/8/7 and the latest Windows 11? You can choose either of those two methods above. If you don’t want to reinstall OS and change startup disk, the second method is a better choice. Besides, AOMEI Partition Assistant Professional has many other advanced features: convert (system) disk between MBR and GPT without deleting partitions, extend NTFS system partition without reboot, split partitions and more. To change Server primary hard drive, you can use AOMEI Partition Assistant Server instead.

FAQs about changing primary hard drive on Windows 10

1. What is the primary hard drive in a Windows computer?

The primary hard drive is the main storage device where the Windows operating system, applications, and user data are installed. It's often referred to as the C: drive.

2. How do I back up my data before changing the hard drive?

You can use built-in Windows tools like File History or third-party backup software to create a backup of your data. Ensure all important files are backed up to an external drive or cloud storage.

3. How do I set the new hard drive as the primary boot drive?

After installing the new drive, access the BIOS/UEFI settings during startup (usually by pressing a key like F2, F10, or DEL). Set the new drive as the primary boot device.

4. What should I do if Windows doesn't boot from the new drive?

Double-check the BIOS/UEFI settings to ensure the new drive is selected as the boot device. Ensure the cloning process completed successfully, and all cables are securely connected.

5. How do I activate Windows after changing the hard drive?

Windows should remain activated if you cloned the drive. For a clean install, you might need to enter your product key or use digital activation linked to your Microsoft account.

Emily · Staff Editor
Emily is an English editor of AOMEI Technology; she has a great passion for providing easy solutions for people to tackle with all disk or partition management problems. In addition to writing articles about disk/partition management, she also edits great tutorials on how to back up and restore disk for data security. In her spare time, she loves to learn computer skill to improve herself or stay with her family to enjoy a good day.