At Download.com, we've long recommended the excellent Mark Russinovich-created and Microsoft-supplied Process Explorer freeware, which provides scads of info on all of your Windows PC processes and options for managing them. Well, Process Lasso is like the peanut butter for Process Explorer's chocolate. It lets users set default priorities and CPU affinities for specific processes, establish rules for how processes behave, and also create alerts and automatic events for when processes misbehave or use too much memory. The interface is outdated and not beginner friendly, but Process Lasso offers very useful features in a powerful little package.
In some ways, Process Lasso is great for newbies -- install it, run it, forget about it, and Process Lasso will moderate the process activity on your computer in order to maintain optimal performance (based on the default configuration settings that make up Process Lasso's ProBalance algorithm). Everyone's computer is different, and to make the most of Process Lasso, I recommend (gasp!) reading the included documentation in order to avoid user-unfriendly messages like "If you don't know what this message means, STOP NOW."
Process Lasso exists as two basic applications -- the core engine (ProcessGovernor.exe), which can be run all by itself; and the graphical interface (ProcessLasso.exe), which allows users to configure Process Lasso, manage processes, and monitor activity. You can use the GUI to configure your rules and settings and then close the interface to let the engine run in the background. (You also have the option to kill the engine when you quit the GUI.)
The main window of the interface includes a list of all PC processes, plus a processor use/responsiveness graph, and meters for CPU and RAM usage. All actions taken by the users or automatically by the ProBalance algorithm are recorded in a running list at the bottom of the screen. When spikes in processor or RAM use occur, Process Lasso highlights the events on the graph in green. One very nice touch is the ability to automatically terminate any process. You might not be able to delete it, but you can stop it from ever running!
The documentation is a bit outdated in parts (a few mentions of "New in v4"), yet comprehensive, and almost required to use Process Lasso effectively. The amount of available settings are overwhelming, which is nice for the power user, but a bit intimidating to normal folks. Once you take the time to learn how the program works, however, I think you'll find it to be an excellent little weapon to add to your Windows freeware arsenal.