Here are some utilities that are useful for testing or repairing flash media:SD Association Formatter
- Running this should be your first step if you have filesystem errors on a card. I recommend doing a Full (Over Write) format.H2Testw
- Test for proper card capacity.FakeFlashTest
- Another capacity test. Direct download link here
- this does much more than just testing; you have a number of filesystem operations available. Be careful!Fat32Format
- For formatting any large storage media to FAT32.Crystal Disk Mark
- Excellent free benchmarking utility for various storage media.