What formatting a drive means
Formatting a drive erases all existing data on the drive and prepares it for new data to be written. The process removes all files, folders, and partitions on the drive, returning it to a blank, ‘factory fresh’ state. Formatting does not actually erase data, but rather removes the file system structure and partition information, making existing files inaccessible. The original data remains on the physical drive until it gets overwritten by new data. Formatting does not keep any existing files or folders – everything is deleted.
The most common reasons to format a drive are to wipe a drive before selling or donating it, erase data before reloading an operating system, start fresh with a clean disk, or resolve file system errors. Formatting completely resets the drive.
When to Format a Drive
There are a few common reasons why you may need to format a drive:
Drive is damaged or corrupted – If your hard drive or external drive is experiencing errors, crashes frequently, or just seems to be acting abnormally, formatting it can help correct these issues. Formatting completely rewrites the drive’s file system, which can fix file corruption or bad sectors. Just be sure to back up your files first!
Want to change file system – The file system controls how data is stored and retrieved on a drive. Common options are FAT32, exFAT, NTFS for Windows and HFS+ or APFS for Mac. You may want to reformat to a different file system for compatibility or performance reasons. For example, formatting a drive from FAT32 to NTFS in Windows provides better security and allows for larger files.
Selling or giving away drive – When selling, donating or gifting a used hard drive or external drive, you’ll want to securely wipe all personal files off of it. The quickest way to do this is by formatting the drive. This prepares it with a blank file system for the new owner.
Back up important files first
Before formatting a hard drive, it is crucial to back up your important files and data first. This prevents permanent data loss when the drive is formatted. There are two main options for backing up files before a format:
1. Copy files to an external drive – This could be an external hard drive, USB flash drive, or other external storage device. Simply copy over the files and folders you want to keep.
2. Back up to cloud storage – Services like Google Drive, Dropbox, or OneDrive allow you to back up files to the cloud. This provides an offsite backup in case something happens to your local files.
After backing up your files, it’s important to double check that the backup contains all the files and folders you need. Try opening some files from the backup to verify they copied over properly. Having a complete backup prevents losing important documents, photos, or other files when the drive format erases everything.
How to Format But Keep Files
One method to format a drive while keeping your files intact is to use partition software to create a new partition, move your files to the new partition, and then format the old partition. Here are the steps:
- Download and install partition software such as EaseUS Partition Master.
- Launch the partition software and select the drive you want to format.
- Use the software to shrink the existing partition, creating unallocated space.
- Create a new partition in the unallocated space.
- Use the software’s copy/move tool to move your files from the old partition to the new partition.
- Once all your files are moved, format the old partition. You can choose quick or full format.
- After formatting, you’ll have your files safely on the new partition and the old partition will be freshly formatted.
This allows you to reformat the drive while keeping all your files intact on the new partition. Just be sure to back up important files as an extra precaution before partitioning and formatting the drive.
Partition software options
When formatting a drive to keep files, you’ll need partition software to resize, move, create, delete, and manage partitions without losing data. There are a few options:
EaseUS Partition Master is a popular free third-party disk partition manager for Windows that enables resizing, moving, creating, deleting, formatting, converting, wiping, splitting, aligning, and optimizing partitions. It also helps clone disks and migrate the operating system.
Windows has a built-in Disk Management utility for basic partition management like creating, deleting, formatting, and extending partitions. However, it lacks more advanced features available in third-party software.
The basic steps for using partition software are:
- Backup important files as a precaution.
- Launch the partition software.
- Select the target drive and desired partition actions like resize, move, create, format, etc.
- Click “Apply” to preview changes and then “Proceed” to commit them.
Carefully follow the software’s instructions when managing partitions to avoid potential data loss. Advanced tools like EaseUS provide more flexibility and safety features compared to Windows’ basic utility.
Choosing a file system
When formatting a drive, one of the main decisions is which file system to use. The three most common options are NTFS, FAT32, and exFAT.
NTFS (NT File System) is the native Windows file system starting with Windows NT. It supports large partition sizes over 2TB and large individual file sizes over 4GB. NTFS has advanced features like compression, encryption, permissions, and reliability. However, NTFS may not be compatible with other operating systems besides Windows (Differences between the NTFS and FAT32 memory card …).
FAT32 (File Allocation Table) is an older file system supported by Windows and Mac. It supports partition sizes up to 2TB and file sizes up to 4GB. FAT32 works across multiple operating systems but lacks some of the advanced features of NTFS. It is a good option for external storage drives to transfer files between Windows and Mac (Difference between FAT32 and NTFS).
exFAT is supported on newer versions of Windows, Mac, and Linux. It supports very large partition and file sizes. exFAT lacks some of the permissions and encryption features of NTFS. It’s a good option for external storage with large files.
When choosing a file system, consider what devices need to access the drive and if large partitions or files are required. Both NTFS and exFAT provide good performance and support for modern large drives.
Quick format vs full format
When formatting a drive, you typically have the option to do a quick format or a full format. The main difference is that a quick format simply empties the file table and marks all space as available for new data. It does not actually scan the disk for errors. A full format takes longer because it scans the entire drive surface for bad sectors and then empties the file table.
According to Explanation of the ‘normal’ and ‘quick’ formats available on Windows, “Quick formats take a few seconds, whereas a normal format procedure can take several hours. The reason for this behavior is explained on Microsoft’s website: ‘A quick format clears only the file table – it doesn’t scan the disk for bad sectors. A full format scans for bad sectors and can take up to several hours depending on the size and format of the drive.'”
In most cases, a quick format will be sufficient if you just need to empty the drive. However, doing a full format is recommended if you suspect there are errors or bad sectors, as it will try to map those out. This helps avoid potential data corruption issues in the future.
Format drive on Windows
There are a few different ways to format a drive on Windows while keeping your files intact. The easiest option is to use File Explorer. To do this:
- Open File Explorer and right-click on the drive you want to format.
- Select “Format” from the menu.
- Choose your desired file system – NTFS is recommended for Windows.
- Check the “Quick Format” box.
- Click “Start” to begin formatting.
The quick format option will format the drive while leaving your files in place. Just be aware that formatting can sometimes result in data loss, so be sure to have backups just in case.
You can also format from Disk Management. To access this, type “diskmgmt.msc” in the Windows search bar and click on Create and Format Hard Disk Partitions. Right-click the drive and select “Format”.
Finally, you can format from the command prompt using the format command. For example:
format E: /FS:NTFS /Q
This will do a quick format on drive E using the NTFS file system. Be very careful when using the command prompt to avoid formatting the wrong drive.
Sources:
How to format your drive on Windows | Support Seagate US
Create and format a hard disk partition – Microsoft Support
Format drive on Mac
The easiest way to format a drive on a Mac is by using the built-in Disk Utility app. Here are the steps:
1. Connect the external hard drive to your Mac.
2. Open Disk Utility. You can find it by using Spotlight or going to Applications > Utilities.
3. In the sidebar, select the external drive you want to format.
4. Click the Erase button along the top menu bar. This will open the erase dialog.
5. Choose a format from the “Format” drop-down menu, such as APFS or exFAT. See Apple’s Disk Utility guide for format options.
6. Give the drive a name.
7. Click Erase. This will quickly reformat the drive.
Once the format is complete, the drive will be ready to use. Any existing files on the drive will be erased, so be sure to back them up first.
Potential issues with formatting
Formatting a drive can be a long process for large drives. The larger the drive, the longer it will take to complete the formatting process. For multi-terabyte external hard drives, it may take many hours to format the drive.
There is also a risk of data loss if the backup fails or is incomplete. Before formatting, it is critical to ensure all important files are fully backed up, or those files could be lost forever. Double checking the backup and even doing multiple backups is recommended when formatting a drive with important data.
External drives formatted on one operating system may need reformatting before they can be used on another OS. For example, an external drive formatted for Mac OS will typically need to be reformatted to work properly in Windows. The reformatting erases all data, so backups should be done first if moving an external drive between Windows and Mac.
