I used a 16 gb sd card to installl retropie in my raspberry pi 3, but now my computer says its just a 240 mb card. How do I format it to the original state?
When you write an RPi OS image to a SD-Card, it actually creates two partitions. The first one (
/boot) has a 256MB size and because of the filesystem which is
FAT32, is accessible for your Windows box. The second one (
root) has whole other size of the SD-card and formatted as
EXT4 filesystem and because of that you can't see there.
It's the output of
fdisk -l (8GB SD-Card):
Device Boot Start End Sectors Size Id Type /dev/mmcblk0p1 8192 532479 524288 256M c W95 FAT32 (LBA) /dev/mmcblk0p2 532480 15466495 14934016 7.1G 83 Linux
To fix it, you should use a tool like "SD Card Formatter". Check this link out for more information.