Yesterday I traded some files with a friend by hooking up an external hard drive to his computer. I had created a folder with some files in it for him, and likewise created another folder for him to copy files into (miscellaneous audio and video files). Everything seemed to work normally. But when I got back home and plugged the drive back into my laptop, my virus protection picked up something strange, but was able to remedy it immediately.
The drive is working normally, and everything else on it is as it should be, but the folder that my friend copied files into is completely empty. Also, the folder I had created with stuff for him is missing entirely, including the folder itself. However, I can see from the amount of memory being used that all the files in both folders are still there somewhere.
To make matters even weirder, a separate .rar file he had copied onto the drive containing some picture files is there, and is working completely normally, so not everything we copied was affected. And as I said, everything else on the drive appears as it should be. I've tried making hidden files visible in my "view folder" configuration, and also tried to do that through the command prompt, but neither had any effect. Has anyone encountered something like this before?