Drive Snapshot http://www.drivesnapshot.de/en/
It's not freeware, but it works great and it has a differential snapshot function. You should be able to create a snapshot of your master install. Install the next software package. Make a differential snapshot. Shake and repeat. When you're done, you'll be able to mount the different snapshots using Drive Snapshot's Viewer and make comparisons between the installs, etc.
Have fun!
Slashdot Mirror
Drive Snapshot http://www.drivesnapshot.de/en/ It's not freeware, but it works great and it has a differential snapshot function. You should be able to create a snapshot of your master install. Install the next software package. Make a differential snapshot. Shake and repeat. When you're done, you'll be able to mount the different snapshots using Drive Snapshot's Viewer and make comparisons between the installs, etc. Have fun!