From Jose Antonio Lopez Cano:
JoseFileGui is a simple and light weight application that used to to find out what kind of file is it in unix exists a command "file". The JoseFileGui application was developed to be a front end to file.exe. The installer contains all you need to work. You want to know the file type of any documents, just right click on the unknown file, activate the sub menu "Send to" and within select JoseFileGui.