Hi,
first you should go to the Aminet and get a tool for writing the .ADF's to floppy:
http://ftp.uni-paderborn.de/aminet/aminet/disk/misc/Image2Disk.lhaThen I would burn a CD-Rom on your PC containing the ADF's (I think no special format is required, I've read and made a backup of a Windoof 98 installation CD using my Amiga ;-), there was no problem in reading it).
The only problem may be the age of your system, maybe your CD-Rom filesystem at your Amiga is to old and fails to read such an CD or your Amiga CD-Rom may fail to read CDR's. My old TEAC have had problems with CDR's with a silver or gold surface, the blue ones worked well, just try another type of CDR if you have I/O errors while reading them...
Noster