|Windows Vista has built-in capability to unzip zip folders and files, but obviously it cannot unzip them to your backup CD. They have to be unzipped to your hard drive.|
You don't need WinZip to do it, like I said Windows Vista can do it anyway.
First create a new folder on your desktop.
Now copy a zip-folder from your backup CD to the empty desktop folder.
Right-click that zip-folder that's on your desktop and choose "Extract all".
When the dialog-box appears, click "Extract".
You should now see the files from that zip-folder.