Verify files

With File verification tools you can easily check whether a file is corrupted or not.

This type of tools come handy when downloading files from the Internet -- files get corrupted during the transfer quite often. Another good reason to use file verification tools is to ensure the authentity of a downloaded software item -- most software developers list MD5 checksum strings on their official websites and you can then compare the downloaded version's checksum against that string. If the string doesn't match, the downloaded file is either corrupted or somebody has managed to alter the installation file (in worst case scenario, to include viruses or other malicious elements).