NOTE: Before performing any significant repairs, back up your computer's hard drive.
The simplest way to partition your new or existing hard drive is with Windows’ built-in Disk Management tool
Step 1: Use the Windows search box to search for “Disk management” and select “Create and format hard disk partitions” from the results box. Alternatively, use the Windows “power user” menu (Win key + X) and click “Disk management.”
Step 2: Select the hard drive you want to partition from the list of available drives. If it is a new drive, skip to Step 4. If it is an existing drive with files and even your operating system installed on it, you’ll need to create some “unallocated space” before you can partition it. Right-click it and select “shrink volume” from the resulting drop-down menu.
Step 3: Your PC will then calculate how much free space you can allocate to the new partition. Once completed, it will ask you how much of it you want to use. If you want to use all the free space on the hard drive, simply click the “Shrink” button. If you want to specify the size of the eventual partition, input it in megabytes in the respective field, before hitting Shrink.
The process can take a minute depending on the speed of your drive but when complete, you’ll have a new “unallocated” space shown next to the corresponding physical drive in the bottom-half of the Disk Management screen.
Step 4: Right-click the “Unallocated” space and select “New Simple Volume” from the resulting menu.
Step 5: Follow the on-screen instructions and select the size of the volume (the default will use all unallocated space) and the drive letter.
Step 6: It’s wise to format new and old drives when creating a new partition. When given the option, select to do so. For “file system” select “NTFS.” The “exFAT” option is more commonly used for portable devices. You can also add a volume label — name — if you want. You can leave the “allocation unit size” at default. Select “quick format” if you are short on time. A full format is rarely required.
Step 7: Continue to click through “Next” buttons and finally, hit “Finish” to create the volume. Your hard drive will now have a brand new partition with its very own designation. You’ll be able to see it, and all the information about it, on the Disk Management page.