This post introduces 2 ways to allow you to unformat an SD card.
Learn how to unformat SD card or memory card and recover files on it with free data recovery software.
Way 1.

You should immediately stop storing new files to the SD card to avoid dataoverwritten.
If the SD card is overwritten, then its nearly impossible to get back lost data.
MiniTool Power Data Recoveryis an easy-to-use data recovery program for Windows.
in a few clicks.
Formatted or corruptedSD card data recoveryis also supported.
It is a 100% clean tool.
MiniTool Power Data Recovery FreeClick to Download100%Clean & Safe
Step 1.
Use an SD card reader to connect the SD card to your Windows computer.
(Related:Fix SD card not showing up on Windows 10)
Launch MiniTool Power Data Recovery.
This software will automatically scan all data from the formatted SD card including deleted and lost files.
Let the scan finish.
Way 2.
Check the steps below.
PressWindows + R, typecmd, and pressCtrl + Shift + Entertoopen elevated Command Prompton Windows 10. chkdsk E: /f, and press Enter to execute the command.
This command willscan and fixerrors on the SD card.
Wait for the command to fully complete.
At last, typeF:>attrib -h -r -s /s /d *.
*command, and press Enter.