Thanks to jpollard, but there were no such files included in the two downloads I performed.
Thanks also to parish, but I did not download from that mirror, or, indeed, any other that I know of; nor do I recognise any of the iso file names you have quoted. (I confess that I don't understand much about mirrors, and I have never used them for any other downloads of anything. I have on many occasions tried to use bit/uTorrent, but have found the performance to be so poor as to be virtually useless in practical situations.)
The following are the addresses for my two downloads, which appear to me to be authentic from the fedoraproject.org site:
Gnome version:
http://download.fedoraproject.org/pu...-i686-Live.iso
KDE version:
http://download.fedoraproject.org/pu...6-Live-KDE.iso
I repeat, these two downloads did not include checksum files.
Please can someone help further? I really haven't time to spend on installing distros for which my downloads may have been defective.