do you know what type of file it is? if it's not an image, program, document, etc. file then it is probably a file that came with your computer as part of the coding or something. try checking the save date on the file (it should show up if you hover your mouse over it, if you have a pc) and if the date is around the time you got your computer, it's most likely nothing to stress about. if the save date is later, you should google it or go to a computer store.