What does this program do, again? And this one? And this one...?

I’ve had my current computer for about 6 years. Amazing, right? I’m an early adopter when I can afford it, and I totally lucked out on a decent mobo and CPU. During this time, I’ve gotten a program here and a program there and now I have 149 of them. Some I use more than others and some I’ve forgotten what they’re for! I’d like to streamline the whole shebang in as efficient a way as possible until I can have a new system built. That might be a while yet. :\

Is there a tool or widget available that will help me suss out what the programs do (and if there’s an update, should I want to keep it) without my having to run each app? If there isn’t, what would the tech-savvy Jellies suggest I do to make this task less of a slog? I run XP SP3.