What to do with a corrupted SD card: reformat it or trash it?

"Start by using a utility like fsck or chkdsk to check the file system for bad sectors. If you don't find any, that implies the corruption was caused by a transient data problem, and might be safe to reuse--although I wouldn't use it to store anything irreplaceable. Bad sectors might indicate a deeper problem with the media.

If it were me, actually, I'd probably just chuck it either way, unless money were particularly tight. Even a 16GB card can be had for about $30 (US) these days. The problem may never recur, but you have to weigh the value of your time in dealing with it if it does."

"It'll be corrupted in one of two ways. First, the hardware could be failing. If this is the case get a warranty replacement, or throw it out.

Second, the data stored on it is corrupted. Either something wrote garbage to it, or more likely, it was removed before the OS had finished writing all it had in it's disk buffers. All modern operating systems us write-behind caching, where disk writes are stored in memory buffers, and written to disk later. This makes a big difference in response times. If you removed the SD card before all this was written, then could explain he corruption.

So how do you tell if it's a hardware failure or not? As other replies have said, chkdsk/fsck or another program to test it; reformat it and do a write/read test; or just reformat and us it for non-critical stuff."