Although hard drive capacities are constantly increasing, all of those extra partitions do seem like a bit of a waste of space. A new computer that ships with Windows 10 preinstalled typically comes with at least two extra partitions in addition to the one you use every day for storing your files and programs. However, even if you carry out a clean installation on a formatted hard drive, Windows will still create several small additional partitions for various purposes. Some of these partitions are required for the operating system to work correctly, but others may be safely deleted under certain circumstances.
OEMs (original equipment manufacturers) typically divide system hard drives into multiple partitions, primarily for backup and security purposes. Windows will also create its own partitions during installation, and performing an upgrade from a previous version may also make modifications to the partition structure. A typical computer, particularly a new one, may have some or all of the following partitions:
- A Windows recovery partition, typically occupying around 1 GB of space.
- A small EFI system partition of a few hundred megabytes.
- An OEM partition of 1 GB or greater for storing backup files from the computer assembler.
- One or more additional recovery partitions for restoring the computer back to default factory settings.
In most cases, none of the above will be visible in Windows Explorer, since they won’t have drive letters assigned to them. However, if you find your hard drive capacity is much lower than advertised, then it likely has several hidden partitions. You can view the partition structure of your hard drive by opening the Disk Management utility.
If you don’t mind taking the risk, you might be able to reclaim a significant amount of space by deleting unwanted partitions and extending your primary partition using the reclaimed space. If you’re using a low-capacity solid-state drive, you’ll likely want to get as much storage space out of it as possible, but it is imperative that you know exactly what you’re dealing with before you delete anything.
EFI System Partition
The EFI System Partition is usually the first one in the list as displayed in Disk Management. Since you can only extend partitions forwards, deleting any that come before the primary partition is usually pointless, since you would have to create a separate partition anyway. The EFI System Partition should never be deleted, since it contains critical files required for booting Windows. Deleting it will leave you with an unworkable machine. You may also have a small Recovery Partition between this one and the main partition where Windows itself is installed. However, you should avoid deleting or modifying this one as well.
If you have upgraded to Windows 10 from an earlier version, you’ll likely have a recovery partition straight after the main partition. You will need this one if you ever need to reinstall Windows, although deleting it won’t prevent you from installing Windows from scratch from a USB drive or optical disk. However, while it is not strictly necessary to keep this partition, Windows does not allow you to delete or modify it using the built-in Disk Management utility. However, you will need to remove this partition if you want to extend the primary partition into any unallocated space after. The only way to delete this partition without using third-party software is to create a recovery drive and then ask Windows to delete the recovery partition afterwards. You can find the necessary tool by typing ‘recovery drive’ into the start menu. You will need a USB flash drive with at least 16GB of free space to continue.
You’ll likely have at least one more recovery partition that contains the original operating system and software that came with your computer, particularly if you upgraded to Windows 10 rather than performed a fresh install. If you’ve upgraded, this partition is likely worthless, since it will contain outdated software and system files that you’ll never have any use for unless you intend to restore the computer to its factory default software. However, keeping the partition is still quite pointless, since your license to use the older version of Windows stored on it expires a month after you have been using Windows 10 anyway.
Any further partitions will likely have been put there by previous operating systems or OEMs. They may contain other versions of Windows or even entirely different operating systems altogether. Provided you know what’s on them, you can delete or retain them as you require.
If you do decide to tinker with the partition structure of your hard drive, you must be absolutely sure that all of your important files are safely backed up on an external storage device. For best results, create a complete system image backup to ensure that nothing gets forgotten about.