SystemSherlock Lite

From Kephyr:

SystemSherlock Lite is a free command line utility designed to analyse changes made to the registry and file system on your Windows workstation. SystemSherlock Lite saves an image of the registry and all your files and folders. Later on - for example after installing some software - you can analyse in detail what changes have been made to your system. You will find out exactly which registry entries and files that have been created, deleted or modified.

Very useful to monitor program installations or to keep track of which files and registry keys are tampered with over time. Uninstalling trojans, spyware, viruses and keyloggers is an easy task when you know what modifications the software made to your computer.

You can easily specify which parts of the file system and registry you want to monitor using the command line options and the powerful regular expressions feature.