We all know how messy the Window's Registry is. It could cause your system to slow down, crash or even stop booting up completely.
Regshot is a light-weight, open-source utility that can take snapshots of the registry and compare it with another clean snapshot taken at an earlier stage, when the system was known to have been working properly.
This could come in handy while investigating issues that come up after the installation of a new software, or just to know what happens behind the scenes. From a security perspective, it is a handy tool to keep an eye on your registry and be forewarned in case a virus or a trojan messes up your machine.
Grab your free, portable copy at: http://sourceforge.net/projects/regshot/