- Insert your SD card into your computer
- If the SD card has any files and folders on it, copy everything to a folder on your computer
- Run
SD Card Formatter Setup
(the.exe
file) in the downloaded .zip file with Administrator privileges, then install the program - Run
SD Card Formatter
from the Start Menu - Select your SD card’s drive letter for "Select card"
Make sure you choose the correct drive letter, otherwise you might accidentally erase the wrong drive! - Ensure that "Quick Format" is selected
- Click "Format"
- Click "OK"
- Wait for the format to finish
- Click "OK"
- Close SD Card Formatter
- Run
guiformat.exe
- Select your SD card’s drive letter for "Drive"
Make sure you choose the correct drive letter, otherwise you might accidentally erase the wrong drive! - Select a size for "Allocation unit size"
- If the SD card is 64GB, choose 32768
- If the SD card is larger than 64GB, choose 65536
- Ensure that "Quick Format" is selected
- Click "Start"
- Click "OK"
- Wait for the format to finish
- Click "Close"
- If the SD card had any files and folders on it before the format, copy everything back from your computer
Your SD card will be formatted to exFAT at this point. The following steps will format it to FAT32. |
Common errors with guiformat
Failed to open device: GetLastError()=32
Close everything that may be using the SD card, such as any File Explorer windows. If it does not resolve the issue, try formatting the card to NTFS, then run GUIFormat again.