Everybody has a bunch of programs loaded on startup. Useful tools, like virus scanners, download managers and system protection applications; not-so-useful programs like messengers and mouse cursor enhancements; complete crap like screen toys, for example. All those programs share one property - they load every time you boot the computer up. Windows Startup Manager, or WSM, will help you control over what's going on during startup, thus saving valuable memory for other applications and making the system more stable on the whole.
WSM is not resident: it consists of two modules. One is the configuration module where you create profiles and the other one is the boot-up module which runs on startup only. Creating and editing a profile is quite easy - you see the list of things that load every time you boot up, pick the ones you need and discard the others, leaving them at rest in the default profile.
Use this program for tweaking the system to better performance - WSM can make any program run as the only thread in the system. Other less impressive features include an alternative password system and a reminder tool similar to the standard Windows Task Manager.
WSM is shareware: try the full version for 15 days. After that, unless you pay, of course, some features will be disabled.