I've noticed that after installing new programs onto my computer it significantly increases load times, and even programs that don't loadup something on startup. I mean when I did a fresh install of just Windows and nothing else, the loading bar from the Windows screen would only scroll across once before the OS booted up to my desktop. After installing more and more program it takes the blue (or green if you're using Windows XP Home) bar to scroll across many more times. Why is that, especially if the programs don't have anything that loads on startup? Here's a picture of the load screen if that was confusing:
As for after startup and it starts loading up startup programs and stuff, that I don't really care about, since you can go into that menu to turn off certain programs you don't want starting up, but what's with the loading time increasing? What is it about installing new programs that makes it go so slow? It already goes slower when it's loading programs at startup.
Jam it back in, in the dark.