Some (not all) CD applications can be run from hard drive by copying CD to drive and installing from there.

If you try this, I advise creating a separate partition for each CD Application. Use some utility like Partition Magic, which will resize, move, create, and delete partitions. Partitions with data can be resized and/or moved without losing the data.

Also, you can get Windows Explorer to display an Icon of your choice with each hard drive in the Tree View on the left side of the Explorer window. Do this by creating an autorun.inf in the root directory.