Regshot is a small,free and open-source(GPL) registry compare utility that allows you to quickly take a snapshot of your registry and then compare it with a second one - done after doing system changes or installing a new software product. The changes report can be produced in text or HTML format and contains a list of all modifications that have taken place between snapshot1 and snapshot2. In addition, you can also specify folders (with sub filders) to be scanned for changes as well.