Why flash drive ask to be formatted?

Sometimes, your computer will ask you to format the USB flash drive. That's to say, your flash drive may be corrupted or damaged. And you are not able to open USB stick and the data on it.

Then, I will list the common scenario in the following.

  • USB drive holds bad sectors and displays "disk needs to be formatted".

  • USB drive is blank or has an unsupported file system.

  • "Please Insert Disk into Removable Disk".

  • USB drive shows 0 bytes or "folder is empty".

  • The virus has infected the flash drive and corrupted the files in it.

  • "USB Device Not Recognized or Malfunctioned".

  • "You need to format the disk before using it".

When you receive one of the message above, you need to backup files before formatting first, then you have a chance to recover files from corrupted drive. If you directly format USB, all your files will go forever.

How to fix a corrupted flash drive without formatting?

How to recover files from a flash drive without formatting? How to fix a corrupted flash drive without losing data? Both are the main concerns of users.

Don't worry about it. See below and I will help you solve the problems via two parts. The first part is to recover files and then to fix corrupted USB drive in Windows 7/8/10.

Part 1: Recover files from a flash drive without formatting

Solution 1: Recover files from USB using CMD attrib

Step 1. Open CMD. You can press Win + R to summon the Run window, then type cmd.exe and click OK.

Step 2. Check if your drive has bad sectors. In the command prompt, type the following command and hit Enter.

chkdsk H: /f (H is the drive letter of USB drive. If your drive has a different drive letter, you can replace it.)


Step 3. Type Y If the drive is in use and hit Enter key to proceed. If the CMD does not prompt, you can see Step 4.

Step 4. Get the deleted files back. You can type the following command and press Enter to run it.

attrib –h –r –s/s /d H: *.*


-h command assigns the Hidden attribute to the selected files.

-r refers to Read-only attribute: files are readable and cannot be changed.

-s assigns System attribute to the selected files.

/s implies to search the specified path including subfolders.

/d command includes process folders.

After all operation finish, you will find that all the recovered files are saved on your USB drive with a newly created folder. By default, the files will be in .chk format. But you still can change the file format and save it at the preferred location.

Solutions 2:Recover files from backup image and data recovery software

If you create a file backup before you format the drive, you can restore it from the backup image. You can open AOMEI Backupper Standard, click Restore at the initial screen, click Select Task or Select Image File to find the backup image, then select the files or folders you want to restore and decide where to restore the file, click Start Restore. After that, you can use data recovery software like Recuva, which can scan and recover your files. And it’s free and works fine.


If you create other backup image, such as, disk backup, partition backup, you still restore file the image. AOMEI Backupper offers you a feature called Explore Image that can allows you to do selective file restore via virtual partitions. Besides file restore, you still can restore system, disk, partition. The premise is that you must have a system backup, disk backup, or partition backup. If you do not have a backup, you can create one with AOMEI Backupper Standard.

If you want more advanced features, you can upgrade to AOMEI Backupper Professional. It supports all kinds of Windows-based operating system, including Windows 7/8/10/XP/Vista. If you are using server-based computer, you need to download AOMEI Backkupper Server instead of AOMEI Backupper Professional. If you want to protect unlimited computers within your company, you can pick AOMEI Backupper Technician or Tech Plus. With the inbuilt AOMEI Image Deploy tool, you are also allowed to deploy/restore system image file on server-side computer to multiple client-side computers over network.

Part 2: Fix a corrupted USB without formatting it

Follow the below guide to repair, you have 3 ways to take a shoot:

Solution 1: Test different USB ports on different computers

USB port can be one of the reasons that your flash drive does not work properly. I recommend you to check the USB port.

Solution 2: Assign a drive letter for USB

Sometimes, the computer cannot assign a drive letter for external USB drive owing some unknown reasons.

Thus, you can plug your drive into the computer and manually assign a drive letter for it.

Detailed steps:

Step 1. Press Win + R to open the Run windows and type diskmgmt.msc

Step 2. Right-click your drive, select Change Drive Letter and Paths from the context menu.

Step 3. Click Add, select a drive letter in the drop-down menu and hit OK.

Step 4. See if you can open your drive and access your data.

Note: some users report that they cannot press Change Drive Letter and Path. There are two main reasons for it. First,the file system of USB is not FAT32 or NTFS. Second, the USB is write-protected. Thus, you can turn to a third-party tool like AOMEI Partition Assistant and change drive letter with it.

Solution 3: Fix corrupted USB on windows 10/8/7

In Windows 7/8/10, there is a disk check utility, which will scan your disk to find system errors and bad sectors and fix it. If there are bigger that it can’t fix, it will show you.

You can make use of the Properties of the drive and it will take you to disk check interface. In different Windows, there is a little difference in expression. But, the steps are basically the same and you can follow the steps below.

Step 1. Connect USB drive to PC.

Step 2. Open Computer or This PC, right-click Removable Disk and open its Properties.

Step 3. Click on Tools, tick the Check Now option and check Automatically fix file system errors and Scan for and attempt recovery of bad sectors.

Win7 Properties

Step 4. Click Start to begin the scan process. Wait and click Close once the process complete.

Solutions 4: How to fix a corrupted flash drive without formatting using CMD?

Step 1. Go to command prompt, type chkdsk H: /r and hit Enter to run it.

Step 2. Wait patiently and type exit to leave this window if there is no problem.

Solutions 5: Fix a corrupted USB drive with Device Manager

Step 1. Go to Control Panel and Device Manger. Also, you can directly type device manager in the search box and select it from the result list.

Step 2. Expand Disk Drive list and right-click on the USB drive and choose Enable, then wait patiently.

Enable Usb Drive

A little advice - What if you format USB flash drive?

When you are asked to format your USB drive, you can format it or not. In general, I will recommend you not to format it before you recover the files. But, there are some people who may accidentally format it.

Don't panic. Even if you format the USB thumb drive, you still can restore your data. Because every file has its structure, including directory and blocks. When you format the drive, you just remove the directory of it. All your files are marked as unimportant and keep intact here.

You need to pay attention to the following things.

1. Stop using the USB drive.

2. Do not add new items to USB stick.

3. Do not reformat the USB flash drive.