How to Format a USB Drive (And Why You Would Need To)

How To Format A USB Drive In Windows

Formatting a USB drive is easy. Our guide explains the easiest and fastest ways to format a USB drive on a Windows computer.

Whether you're running Windows XP, Windows 7, Windows 8.1, or Windows 10, the steps are essentially the same.

1. Plug in the USB drive.
2. Open Windows File Explorer and go to This PC (aka Computer or My Computer).
3. Right-click the drive, and select Format...

The formatting options you can customize are File system, Allocation unit size, Volume label, and Format options. You can also Restore device defaults in case your custom settings aren't working. 

To format your drive, you simply make your selection, click Start, followed by OK to confirm that you really want to erase all data and the drive will be formatted. 

However, before you proceed with formatting, you will want to understand what each of these options actually means. So let's go through them one by one.

Which File System To Choose?

In Windows 10, you will see a maximum of four different file systems: NTFS, FAT, FAT32, and exFAT. You will not see FAT and FAT32 if your drive is larger than 32 GB. So what is the difference between those file systems and which one should you choose? Let's look at the benefits of each.

NTFS Compared To FAT & FAT32:

1. read/write files larger than 4 GB and up to maximum partition size
2. create partitions larger than 32 GB
3. compress files and save disk space
4. better space management = less fragmentation
5. allows more clusters on larger drives = less wasted space
6. add user permissions to individual files and folders (Windows Professional)
7. on-the-fly file encryption using EFS (Encrypting File System; Windows Professional)

FAT & FAT32 Compared To NTFS:

1. compatible with virtually all operating systems
2. takes up less space on the USB drive
3. less disk writing operations = faster and less memory usage

ExFAT Compared To FAT & FAT32:

1. read/write files larger than 4 GB
2. create drive partitions larger than 32 GB
3. better space management = less fragmentation

Due to its nature, FAT or better yet FAT32 are suitable for drives smaller than 32 GB and in an environment where you never need to store files larger than 2 or 4 GB, respectively. In other words, any regular sized hard drive (60 GB +) should be formatted with NTFS.

However, due to the way NTFS works it is not recommended for flash drives, even when they are bigger than 32 GB. This is where exFAT comes in. It combines the benefits of FAT (small, fast) and NTFS (large file size supported) in a way that is perfect for flash drives.

Keep in mind though that FAT and FAT32 are the only file systems that are cross-platform compatible. NTFS is supported in Linux, but it requires a hack or third-party application to work on a Mac. exFAT, on the other hand, is supported as of OS X 10.6 (Snow Leopard), but you need drivers to read it on Linux.

If for compatibility or speed reasons you want to go with FAT or FAT32, always go with FAT32, unless you are dealing with a device of 2 GB or smaller.

Which Allocation Unit Size Works Best?

Hard drives are organized in clusters and the allocation unit size describes the size of a single cluster. The file system records the state of each cluster, i.e. free or occupied. Once a file or a portion of a file is written to a cluster, the cluster is occupied, even if there is space remaining.

Hence, larger clusters can lead to more wasted or slack space. With smaller clusters, however, the drive becomes slower as each file is broken up into smaller pieces, and it takes much longer to draw them all together when the file is accessed.

Hence, the optimal allocation unit size depends on what you want to do with your USB drive. If you want to store large files on that drive, a large cluster size is better as the drive will be faster. If, however, you want to store small files or run programs off your flash drive, a smaller cluster size will help preserve space.

Rule of thumb: large drive and/or large files = large allocation unit size (and vice versa)

For a 500 MB USB flash drive, rather select 512 bytes (FAT32) or 32 kilobytes (FAT). On a 1 TB external hard drive select 64 kilobytes (NTFS).

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