Windows only: FileCheckMD5, a free stand-alone utility, is designed as a simple means of generating and comparing two MD5 files against each other for verifying burned CDs/DVDs. Because it's a stand-alone program that can run from any directory, however, it makes for a nice addition to the root of any disc you're burning and passing along. Throw the app and your original MD5 (from the files you burned for them) onto the disc, and they can check if any problems they're having are due to a bad burn. It's a simple, fast, and free tool for anyone who does a good deal of burning. FileCheckMD5 is a free download for Windows systems only.