it could be the file that stores all of the thumbnail images for your files. i am not sure
I have a file called thumbs.db, that shows up in different places all the time. Sometimes it is on my desktop, sometimes in the drop down list of files in a folder, and today it appeared in a sharing folder in MSN Messenger. If I try to move it I get a window asking if I really want to move a database file. Can anyone tell me about it?