If your Switch microSD card is corrupted, act quickly to recover data. First, stop using the card immediately—continued use can overwrite lost files. Connect the card to a PC via a card reader and use data recovery software like Recuva, EaseUS Data Recovery Wizard, or Stellar Data Recovery. Launch the software, select the microSD card as the scan location, and run a deep scan (this takes longer but finds more files). Preview recoverable files (focus on game saves, screenshots, and videos) and save them to your PC’s hard drive. After recovery, reformat the microSD card to exFAT using your PC or Switch—go to 'System Settings' > 'Data Management' > 'Manage MicroSD Card' > 'Format'. If recovery fails, the card may be physically damaged—replace it with a reputable brand (SanDisk, Samsung) and regularly back up data to the cloud or PC.