If the software does not recognize the backup CD-R, I would try making a data folder using the old name from previous installation and then see if the backup will work with the folder already named. That is about all I can think of unless your backup CD is somehow defective and not recognized.
I use Address Book 6.0 and have done this before... it does work.
Using Windows ME. I formated my hard drive to get rid of virus. Trying to reinstall Address Book 6.0. I backed up AB on CD-R before formating and have the Address Book 6.0 CD. AB installation appears okay, but having trouble getting it to accept backup info.