NT-based versions of Windows normally does not create a Recycle Bin on a
removable flash drive; however, some users have added a Recycle Bin by
using iBin (there may be others but I only know of this one). It has
been a l-o-n-g time since I last used 9x-based versions of Windows but
recall those add a Recycle Bin for every drive except for the A: and B:
drives (floppies). I've read (never used it) that iBin deletes the
hidden Recycle Bin folder to then use its own deleted files store. I'm
using Windows 7 and, I believe, from Vista onward this folder was named
$Recycle.Bin; however, back in XP it was called Recycler.
"Hidden" only means that it is not normally visiable. In Windows
Explorer, you have to disable the "Hide protected operating system
files" option to see the Recycler folder. That's in Win7. Back in
WinXP, you may only have a "Show hidden files" option. I don't have an
XP host to check. In a command shell (aka DOS prompt), you could run
"dir <drive>:\ /adh" on the root folder of a drive to see the
directories (folders) with the hidden attribute enabled on them.
Some malware, like Conficker/DownAndUp, would create the hidden-flagged
recycle bin and also use a hidden-flagged autorun.inf to spread via
removable drives (i.e., USB flash drives). Tis one of the reasons why
you should disable AutoRun on all removable drive types (not AutoPlay
but AutoRun) in Windows on your desktop/laptop.
iBin
http://www.autohotkey.net/~FirstToyLab/
no longer exists but its Sourceforge site is still alive at:
http://sourceforge.net/projects/ibin/
You could delete the hidden-flagged folder by opening a command shell
(with elevated privileges on Vista, and later) to run:
rd /s <drive>:\Recycler
Add the /q parameter if you don't want to be prompted to allow the
deletion. Windows recreates the folder when it next wants to save
deleted files. Nirsoft lets you also empty the Recycle Bin from the
command line using "nircmd.exe emptybin". That empties the recycle
folder on all drives.
http://ss64.net/westlake/xp/index.html has more
options, like listing the contents and supposedly showing before and
after statuses (but I never used that one). Emptying the Recycle Bin
using Windows Explorer (either in the file manager GUI or using the
desktop icon) may not empty out all files from that folder.
While you're at it in a command shell, and after deleting everything,
run "dir /ah" and "dir /adh" on the root folder of the flash drive to
see if there are other hidden-flagged files or folders you missed.
If you, at some point for the flash drive, don't have any files on the
flash drive that you want to keep or, in your case, you have deleted
them all, what does the flash drive's properties report after doing a
quick format of it?