Some days ago I mounted my External Hard Drive to the Friend's Laptop (WinXP), Then all Folders on the Hard's root have been hidden (on all Windows Versions).
therefore to access them you should know their exact address and type in address bar OR make hidden folders visible by change default settings in folder options like below image.
Any Other Hard Drive or flash disk that mounted to that laptop have been same condition. So I scanned whole of the Drive by an Updated Anti-malware (Kaspersky Internet Security) but no threats infected.
Did a malicious cause that?
How to Back to previous state?