Problem: a virus reached your flash drive (maybe even your entire computer) and hid all you folders. You may even see that your folders have been replaced by a shortcut icon (one with a black arrow in the lower corner). After removing the virus, the folders can't be unhidden and the property check boxes do not respond.
Solution: Use a command prompt to change the attributes.
1) Open the command prompt by going to Start > Run and typing "cmd". A black screen will open.
2) Type attrib -s -h /S /D x:\
NOTE: x:\ should be the drive indicating your flash drive that has the hidden folders.
Open the flash drive again and your folders should now be visible again.
Solution: Use a command prompt to change the attributes.
1) Open the command prompt by going to Start > Run and typing "cmd". A black screen will open.
2) Type attrib -s -h /S /D x:\
NOTE: x:\ should be the drive indicating your flash drive that has the hidden folders.
Open the flash drive again and your folders should now be visible again.