What to do if you get that scared alert? How about all of your important data that hasn’t been backed up yet? Today, one of my USB stick has that problem and I searched around for help. And here is the solution
1. Download this program: TestDisk
2. Follow the instruction here: http://www.cgsecurity.org/wiki/TestDisk_Step_By_Step
It’s 10 minutes operation only. Remember to take the usb out after finishing and plug in again to see your data came back.
Hope that helps!