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Give your computer a fresh start by wiping and reformatting your primary hard drive on Windows or macOS
This guide teaches you how to format your computer's built-in hard drive, which differs from formatting an external or secondary hard drive. To completely erase and format the hard drive where Windows or macOS is installed, you'll need to do so from outside the operating system. For Windows users, creating a recovery drive is necessary. Mac users have built-in tools for formatting the system drive. Alternatively, you can create and format a new partition on the same drive without losing any data if you prefer not to erase your operating system.
Important Considerations
- Prior to reformatting your primary hard drive, ensure all crucial data is backed up to prevent loss.
- When reformatting on Windows, boot with recovery or installation media to erase the drive from outside the operating system.
- For reformatting on a Mac, reboot into Disk Utility to erase your primary hard drive and reinstall macOS.
Steps to Follow
Reformatting (Windows)
Make a recovery drive. To format the hard drive with Windows installed, you'll need to do this outside the OS. Boot from a recovery disk, typically a USB flash drive or DVD. Here's how:
- Insert a blank USB flash drive (16 GB or larger) or DVD.
- In the Windows search bar, type recovery and select Create a recovery drive.
- Select 'Back up system files to the recovery drive' and click Next.
- Choose your USB drive and click Next.
- Click Create.
- Keep the USB drive plugged in for booting.
Back up important files. Since formatting erases all data, backup vital files first. Learn how to back up your data in Windows 10.
Set PC to boot from USB. If unsure, follow these steps:
- Go to Settings > Update & Security > Recovery.
- Under 'Advanced,' select Restart now.
- Access UEFI Firmware Settings under Troubleshoot > Advanced options > Restart.
- In BIOS/UEFI, find Boot or Boot Order.
- Set USB drive as the first option.
- Save and exit (usually F10).
Boot from USB. If BIOS/UEFI settings were changed, your PC will boot from USB. Choose Boot from disk when prompted. If settings weren't changed, restart and select Boot from disk.
Choose your location preferences and click Next. Once you've selected your language and regional settings, clicking Next will prompt you to install Windows.
Click Install now. You'll now go through some welcome screens.
Select Custom on the 'Which type of installation do you want?' window. Proceed through the welcome screen and accept any terms and policies displayed. When you reach 'What type of installation do you want,' click Custom: Install Windows only (advanced). This option is necessary if you wish to reformat the drive.
- No worries—if you backed up your data, you can retrieve it after formatting and reinstalling Windows.
Select the primary partition and click Format. This is the partition where Windows was previously installed, labeled 'Primary.'
Click OK on the warning message. This warning informs you that continuing will result in the loss of any data on the drive or partition. Once confirmed, the selected drive or partition will be formatted.
Remove other partitions (optional). You'll likely see additional partitions on the drive. Keep the system partition untouched as it contains essential boot information, especially for BitLocker. However, you can delete other partitions if unnecessary. This will either convert the area into unallocated space or maintain them separately formatted. To delete a partition, select it and click Delete.
- If you wish to merge the unallocated space with the newly formatted partition, select the formatted partition and click Delete. Then, create new partitions as required by selecting the unallocated space, clicking New, and adjusting their sizes accordingly.
- If you're not installing Windows, you're finished!
Choose your formatted partition and click Next for Windows installation. Now that you've formatted the drive, proceed with the on-screen instructions to perform a clean Windows installation. Once Windows is installed, you can log in with your Microsoft account (or create a new local account) and set up your computer anew.
- You can now restore your backed-up files.
Creating a Partition (Windows)
Access the Windows Disk Management tool. Press Windows key + S to open the Windows search bar, type partitions, and click Create and format hard disk partitions.
- This method won't reinstall Windows but allows you to create and format a new partition on your internal drive.
Choose your hard drive. Click on your hard drive's name in the window at the bottom of the screen.
Click Action. Find this tab at the upper-left side of the window. A drop-down menu will appear.
Pick All Tasks. Located near the bottom of the drop-down menu, you'll see a pop-out menu appear to the right.
Tap on Shrink Volume…. Positioned in the middle of the pop-out menu, this option will open a new window once Windows determines the available space.
- It may take Windows a few minutes to calculate your available space.
Input a size for your new partition. Enter the desired number of megabytes for your partition in the 'Enter the amount of space to shrink in MB' text field on the right side of the page. This will specify the size of the new partition.
- The maximum megabyte allocation is displayed directly above the input field.
- One gigabyte (GB) comprises 1000 megabytes (MB). For a 5 GB partition, input 5000 in the text field.
Tap on Shrink. Located at the bottom of the page, this action will remove a portion of space from your computer's hard drive to create a new 'hard drive' from it.
- This process may take a few minutes to complete.
Select the newly created partition by clicking on the 'Unallocated' section adjacent to the hard drive's representation.
Access the 'Action' menu and opt for 'All Tasks' to proceed. This action will prompt a pop-out menu to appear once again.
Navigate to 'New Simple Volume...' from the menu options and initiate the process. This action will trigger a new window to open up.
Proceed by selecting 'Next' positioned at the bottom-right corner of the window.
Confirm your partition size by selecting 'Next,' subsequently advancing to the succeeding page.
Choose a drive letter and proceed by clicking 'Next.' If you wish to alter the drive letter (e.g., from 'E' to another), utilize the dropdown menu for selection.
Indicate your preferred formatting settings. Tick the box labeled 'Format this volume with the following settings,' then select your desired file system from the provided options: NTFS, FAT32, or exFAT.
Select 'Next' to advance to the confirmation page.
Click 'Finish' situated at the bottom of the page to initiate the partitioning process. Once completed, the partitioned drive can be accessed like any other within the This PC program.
Reformatting (Mac)
Ensure to back up your crucial data before proceeding. Formatting your Mac's primary hard drive will result in the deletion of all its data.
Determine your processor type, whether it's Intel or Apple silicon. This knowledge is essential for executing the correct steps to format your primary hard drive.
Power off your Mac by selecting 'Shut down' from the Apple menu.
Boot your Mac into Disk Utility following the specific steps for your processor type: Intel or Apple silicon.
Choose your hard drive from the left sidebar, typically named 'Macintosh HD.' If you're using an Apple silicon processor and have added internal volumes using Disk Utility, remove them before proceeding.
Click on the 'Erase' button located at the top of the window.
Provide a name and select a format for the drive. Opt to name it Macintosh HD and choose the recommended format, typically APFS or Mac OS Extended (journaled).
Select 'Erase Volume Group' or 'Erase' if the former isn't visible. Password confirmation may be required. For Intel, delete any additional internal volumes post-erasure, but retain volumes labeled Macintosh HD, Macintosh HD - Data, or those under 'External' or 'Disk Images.' For Apple silicon, click 'Erase this Mac and Restart' when prompted.
Proceed to install macOS on the formatted drive. For Intel, close Disk Utility, select 'Reinstall macOS,' and follow instructions. For Apple silicon, follow post-restart instructions, select 'Exit to Recovery Utilities,' then 'Reinstall macOS,' and continue with setup.
Creating a Partition (Mac)
Access Disk Utility on your Mac by pressing Command + Spacebar, typing disk utility, and selecting Disk Utility from the search results.
Choose your hard drive, typically named Macintosh HD, from the left sidebar. Click on 'Partition' located at the top of the window.
Click on the '+' symbol below the hard drive circle to reveal partition options.
Specify a name and size for your new partition. The name will be its identifier in Finder. Adjust the size by dragging the knob or inputting a value in gigabytes (GB) in the 'Size:' field.
Select a format for the partition from the 'Format' drop-down menu. Options include APFS, Mac OS Extended (Journaled), MS-DOS (FAT), or ExFAT. Choose according to your compatibility and encryption preferences.
Click on 'Apply,' situated in the bottom-right corner of the window, to commence the partition creation process. Please allow some time for this process to complete.
Once the partition format is complete, click on 'Done.' Your Mac's partition has been successfully created and formatted. It will now appear as a hard drive in Finder.
