I have an 8 GB Sandisk Cruzer thumbdrive that I just deleted all the files from. It should show 8 or nearly 8 GB available space but it shows only 8.1 MB. Is there something else that has to be done to free up the space? Thank you for any help you give.
Try emptying the Recycle Bin, it may help.
And if you’re using a Mac, I believe you have to empty your “Trash” while the drive is still connected. Otherwise, it won’t complete the deletion on the dirve.