How can I verify that the downloaded CD images are correct?
If you use jigdo, the image checksum is automatically verified after the image has been generated. For HTTP or FTP downloads, use the md5sum utility to calculate the checksums of the files you downloaded, then compare them to the checksums in the MD5SUMS files which are distributed alongside the jigdo files of official releases. An md5sum program for Windows systems is available as part of the Cygwin suite (install the “coreutils” package), or you may be able to find standalone binaries compiled for MinGW. To ensure that the images were not only downloaded correctly, but are indeed official images, you also have to verify the GnuPG signature on the MD5SUMS files using the Debian GPG keyring. CD vendors are encouraged to do this. If you want to check many CD image files or burned CDs easily on Unix/Linux systems, the checkiso script can be a great help.