How to partition a hard drive in Windows 10, and keep your most important files separate from the rest

 1. Press the Windows key + R on your keyboard to open the Run utility, or search for it in the Start menu.

2. Type "diskmgmt.msc" and press "OK." You can also copy and paste that from this article into the Run utility's text field.

3. A menu will appear with a list of all your hard drives. Right-click on the drive you want to partition and select "Shrink Volume."

4. You'll be asked how much you want the drive to shrink. The amount you enter will be the amount of space left for your new partition. The "total size after shrink" will be the space left in the original partition.

5. Still in the disk management utility, right-click the new box that appears at the bottom of the window — it should say much data you shrunk, and the word "Unallocated." In the right-click menu, select "New Simple Volume."

6. Follow the instructions in the New Simple Volume wizard to create the partition. This will allow you to set the partition's size, and to select the letter it will be assigned.

7. You may be asked which format you want the partition to be in. In nearly all cases, you should select "NTFS." In some other cases, like if you're trying to partition a USB flash drive, you'll want to pick "FAT32."