HashMyFiles is a Portable Free Checksum Calculator created by NirSoft. This Hash Checker works by calculating and showing the MD5, SHA, and CRC32 hashes of a file or files. HashMyFiles supports checking a folder of several files at once or via direct file selection. Users can copy hashes to the clipboard or save them to a text, xml, or html file. Furthermore, users can enable Hash checking via the explorer context menu option. Making it rather simple to check file hashes on the fly via right mouse click. Though the application must constantly exist (usb drive must remain plugged in) for this feature to work.