HashTab

A hash is a file's unambiguous identifier obtained based on different algorithms.

If for whatever reason you need to find out what these codes are, HashTab is an application for Windows that lets you look up the MD5, SHA1, and CRC-32 hashes for any file.

The program adds a tab to the file properties window that calculates the different hashes and shows them on the screen.

Don't worry – you won't have to compare the hashes by hand, character by character, since HashTab includes a function that does this automatically.

You can use HashTab to find out whether a file has been downloaded correctly off the Internet, as some websites include the file's hashes for this purpose.