Quick File Hasher is a free full-scale Windows application that can hash files recursively across a selected folder. Hashing is the process of computing a fixed-length string from a data stream. The stream could be a disk file, packets of data or an email message. To compute the hash of a file, you click the "Select" button and select the file, then click the "San" button. You can pause a process by clicking the "Pause" button.