Refer: https://www.3dprintbeast.com/how-to-format-ender-3-pro-sd-card/
Windows
- Start by bringing the Disk Management window up. You can do this by right-clicking the Start Menu and clicking Disk Management in the menu that comes up.
- Find the SD card in the lists of disks (you should be looking at the bottom pane as the top pane is the list of volumes and not disks). If the labels aren’t helpful, you can figure out which disk is the SD card by looking at the capacity of the disks.
- Right-click the volume(s) that belong to the SD card (they are listed right next to the disk) and delete them. Be warned that this process will wipe all of the data on the card.
- Upon successfully deleting all the volumes, you should see a pane that says “Unallocated” next to your SD card and no other volumes, which confirms that you successfully deleted all the volumes.
- Now, right-click the SD card itself and select Properties.
- Click the Volumes tab in the dialog, and look at the partition style line. If it shows Master Boot Record (MBR), move to step 11. You can close the dialog and go back to the Disk Management window after gathering this information.
- Right-click the Start Menu, choose Windows PowerShell (Admin), and then type diskpart in the command line that came up.
- When the prompt starts showing DISKPART>, input the command
- select disk X
- where X is the number of the disk. You can find this number by looking at the Disk Management window from earlier.
- Upon successfully selecting the disk, you will see the output Disk X is now the selected disk. At this point, all you have to do is to input the command
- convert MBR
- Upon success, you should see the output DiskPart successfully converted the selected disk to MBR format.
- To confirm that the process was successful, right-click the disk in Disk Management, go to Properties, and then go to the Volumes tab once again to check the partition style. If it’s showing Master Boot Record (MBR), all is good.
- Bring the Disk Management window up, right-click the box that shows Unallocated, and choose New Simple Volume. Click Next until you reach the Format Partition dialog, and enable the Format this volume with the following settings radio button. Set file system to FAT32 and conclude the process by clicking Next and Finish, respectively.