Apparently, Windows Vista allows you to create only one set of Recovery Disks. Mine filled up three CDs. I also have a full Vista-generated backup on an external hard drive.
I had a crash a while back, when I was installing a program that didn't like Vista. I was reluctant to use the recovery disks because I was afraid they might restore my computer without the programs I've added, but I was desperate and decided to use the recovery disks anyhow. They worked like a charm, and I don't think I lost anything in the restoration.
-Joe-