These images were used to build other systems. As a backup I keep them here. In this example, each image file will be in a zip container. The container will include the following files: ASL_1.01-20180228-amd64-i386-netinst.readme ASL_1.01-20180228-amd64-i386-netinst.md5 ASL_1.01-20180228-amd64-i386-netinst.iso The readme file will contain login information, and any other notes specific to image. Files that contain the .md5 file extension are checksum files that are used to ensure that the data within a file is complete and has not become corrupt. An MD5 file verifies the integrity of the disk image. If you are using Linux, md5sum will give you the md5 value of the file. In the above example: "md5sum ASL_1.01-20180228-amd64-i386-netinst.iso" should be the same as the contents of ASL_1.01-20180228-amd64-i386-netinst.md5. If you are using Windows "CertUtil -hashfile ASL_1.01-20180228-amd64-i386-netinst.iso MD5" will give you the md5 of the file. There is also a freeware app called HashTab that integrates neatly with Windows Explorer Don't let the number of digits in the md5 scare you. A simple check is to compare the first 4 digits and the last 4 digits. Example: 8044d756b7f00b695ab8dce07dce43e5 Do 8044 and 43e5 match on the two md5 values? If so, you are probably good.