How to format a hard drive

If you are planning on ditching your old computer, formatting a hard drive is almost always a necessary thing to do

Formatting your hard drive may be necessary in a wide range of contexts; for example, if you're selling your PC, or throwing it away. Beyond ensuring your protection - in that sensitive data kept will be removed - there are a handful of reasons to want to 'reset' your hard drive in this way.

You can format a hard drive using a few different methods, and these may often relate to your reason for needing to do so in the first place. Installing a new operating system from scratch, for instance, or being targeted by cyber criminals, are factors that could drive you to wipe it clean.

Considered more of a short-term option, quick formatting will give your hard drive the appearance that all its data and files have been removed - wiping files from the partition you choose to format. It does not scan for any bad segments, areas of the hard drive that may be defective, however.

This method can be used if you're hoping to freshly install an operating system, for example. But since the data that existed prior to formatting will remain on the disk, it's only recommended this method is used if you will definitely keep it.

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There are numerous methods you can use besides this, moreover, which all come with benefits and downsides.


Partitions may seem like separate drives - but in reality, they are just the divisions that appear on a single disk - with every hard drive being made up of at least one, or more, partitions.

There can be any number of partitions on a disk, and having them makes it easier to get to work on one particular section that you need to format without tampering with the data stored elsewhere on the disk. This gives you the flexibility, for instance, to isolate one partition for the operating system installation files. If, however, you are aiming to format the hard drive as one entity, these partitions must first be removed.

What file system?

The file system you use when formatting a hard drive will depend on which operating systems you use.

Windows uses NTFS and Mac OS uses HFS so they're incompatible with each other. A file system called exFAT works with both Mac and Windows. This exFAT is better than the FAT32 file system it supersedes as FAT32 has a maximum 4GB file size limit whereas exFAT can work with files as large as 16EB (exabytes). The exFAT file system also runs better than FAT32.

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