When you installed Windows, did you consciously manage the storage space on your hard drive? Is Windows slow because it's running out of space? Or do you have too little room for backups, while the system partition has many GBs to spare? It may be time to reorganize the free space on your hard drive.

Whether you're trying to install an additional OS, managing multiple storage devices, or expanding your storage space, read on to demystify storage management in Windows 10.

Partitions and Volumes: An Overview

The difference between partitions and volumes can be confusing. But the terminology is important, so let's get it straight.

Any given storage device, such as the hard drive in your computer, contains a single block of free, unallocated space. Before we can make use of this space, e.g. to install Windows, we need to create one or more partitions. Partitions are segmented portions of storage space (full definition of a partition). Typically, Volumes are partitions formatted with a single file system (full definition of a volume).

File systems are ways to organize data in distinct ways (full definition of a file system). With Windows, you'll typically see drives formatted with NTFS (New Technology File System). On removable drives, you'll commonly find FAT32 (File Allocation System) or exFAT. Mac computers work best with HFS+ (Hierarchic File System). The default Linux file system is called ext4 (Extended File System).

If you have two separate partitions (on the same or two different drives) in your PC and both formatted with a file system, both will be labeled with different letters. Typically, you'll have a C: and the D: drive. These two drives are volumes.

For our purposes, it suffices to say you can create a volume from a partition and integrate multiple, unused partitions into a single volume. Installing an OS, for example, will typically create a few partitions: a primary accessible partition, and a secondary recovery partition that boots things (like startup repairs).

Managing Partitions

Now let's look at how you can shrink, merge, and clear partitions in Windows 10. This will let you add or subtract space from your partitions.

Defragmentation

Before you manipulate your partitions, you should first defragment your hard drive. This will gather all your data in a single chunk of space, which can contribute to faster viewing speeds.

Disclaimer: Although defragmenting your hard drive is advised for this process, it's not necessary. Defragmenting SSDs (solid state drives), as opposed to HDDs (hard disk drives), can harm your drive's lifetime, so keep this in mind before proceeding.

To defragment your hard drive, press Windows + S, type defrag, and select Defragment and Optimize Drives from the results. Here you can optimize or defragment your drives. Note that Windows may be set up to do this automatically.

Once you've analyzed and defragmented your hard drive, you'll note the data displayed in your software gathers to one section.

defragment windows 10

The remaining, blank space is what partitioning management tools will use in order to create new partitions. If your data is scattered across the drive, you will not be able to manage the storage space as it's counted with the original partition.

Disk Management

To open Windows 10's Disk Management program, press Windows + S, type partition, and select the Create and format hard disk partition option. In the following window, you'll see both your partitions and volumes laid out in distinct blocks according to your different hard drives.

disk management windows 10

You'll note that the categories above display a series of parameters, particularly Capacity and Free Space. You cannot shrink, or separate, a chunk of storage larger than the free space of your hard drive. Even then, you may not be able to separate the exact free space of your storage because some of the data may be scattered.

So, act accordingly when proceeding with your disk management. Try not to mess with the separate Disk partitions, as they are meant to provide recovery for your installed OSes.

Shrink a Volume

If you have free space on your drive, you can shrink a volume in order to create a separate partition. Right-click on a volume and select Shrink Volume. This will analyze your remaining free space, and prompt you to input how much space you want to shrink (i.e. separate) your volume by.

shrink volume windows 10

Once you've shrunk your volume, you should now be able to see a black space labeled Unallocated in your Disk Management window.

windows 10 unallocated space

That's it! You've successfully shrunk a partition.

Create a Separate Volume

Now that we have a bit of unallocated space, we can create a separate volume. Right-click on your Unallocated space and select New Simple Volume. Follow the Wizard, assign your drive letter, and format this volume into either NTFS or FAT32.

windows 10 new volume

Now, you can use this E: drive in the same way you would a separate hard disk or flash drive. To change the drive letter of this drive, simply right-click the space, select Change Drive Letter and Paths, and follow the wizard. To delete, right-click the Volume and select Delete Volume. Your volume will then revert back to unallocated space.

Format a Volume

At times, you may want to format a volume with a different file system, so you can use it across various operating systems. To do so, right-click on a volume and select Format. In the following window, choose which file type you'd like to incorporate to your volume.

windows 10 format volume

You'll have three different options for formatting a volume:

  • NTFS: The de facto file system for Windows, you can write and view any files you'd like through Windows in this file format. You cannot, however, write onto this file format using a Mac OS distribution.
  • FAT32: The de facto file system for USB drives, FAT32 will allow you to write data from any OS onto this file type. You cannot, however, load individual files larger than 4 GBs onto this file format.
  • REFS: The newer file format of the three, REFS (Resilient File System) grants better protection against file corruptions, may work faster, and maintains a few more benefits like larger volume sizes and file names than its older NTFS counterpart. REFS, however, cannot boot Windows.

Choose your option, continue on with the Wizard, and that's it!

Extend a Volume

When you have a bit of unallocated space, you shouldn't leave that space unused. After all, more space is always better. To expand the storage on your volume using unallocated space, right-click on your existing volume, in my case the D: drive, and select Extend Volume. Follow the Wizard: it should select your unallocated space by default.

windows 10 extend volume

Keep in mind, you can only extend your volume size with unallocated space displayed to the right of your volume within the Windows 10 Disk Management software.

windows 10 original volume size

The process is simple enough and will allow you to use all of your unallocated space.

Demystify Your Storage

Now you know how you can shift storage space from one partition or volume to another. The next time you run out of space on one volume, you don't have to manually move files, you can just add more space.

Got no space to spare at all? It may be time to free up disk space by getting rid of temporary files and other space killers.

If you're just setting up your new PC and wonder how much space Windows 10 will need, we've got you covered.

What did we miss? Can you recommend a third-party partition management software? Let us know in the comments below!