After your friend borrows your SD card to transfer some HD films or apps onto it, you may need to format it to get the memory card clean again. It is best that you format the card with your phone, because performing a format on the PC may cause incompatibilities with your device, which later leads to your SD card being malfunctioned or unusable.
Do these following to format your SD card on the Galaxy Ace:
1. Tap on the Home button to go back to your Idle mode.
2. Now, press on the Apps button.
3. Next, select Settings.
4. Then choose SD card and phone.
5. Next, tap the Storage option.
6. Hit on Unmount SD card pane.
7. Then tap OK.
8. Here, select the Format SD card section.
9. Tap on Format SD card.
10 Finally choose Erase everything.
Notes: remember to always backup all the important data stored on the memory card before you proceed to erase it.