Current file too large for a single backup disk
The file you're backing up is too large to fit on the disk you inserted. This dialog gives you two options to complete the backup. Try option 1 first.
Option 1: Start over
Click Insert a disk with more space and then replace the original disk with one that has more available space and click OK. (Make sure the new disk has no other files on it so it will have the maximum amount of available space.) If it can, Quicken backs up the entire file on the new disk.
Option 2: Continue
Click Back up onto several disks and then replace the original disk with a second disk and click OK. Quicken backs up the rest of the file, placing it on the second disk. Now the backup file spans both disks.