Before I burn an ISO image to disk I always check whether the checksum matches. See
ftp://ftp.freebsd.org/pub/FreeBSD/re...1/CHECKSUM.MD5
Most Unixes or Unix-look-alikes have a program
md5 to check the checksum. For Windows you will have to download such an utility.
You could retry the download from another mirror and burn another disk. Make sure you choose"burn ISO image" from Nero.
But what is so difficult about burning a disk with FreeBSD's burncd? "A whistle of a cent" as a Dutch idiom says
See the announcement of RC2 and the other posts from people having problems with booting the CD's on older PC's
http://lists.freebsd.org/pipermail/f...er/047203.html