Yes, it takes a while. Defragmenting is no easy buisness.
And about the startup programs, yeah, they can often clog your RAM. You could probably just use HijackThis to clear up some startup processes, but only use it if you know what you're doing or are being helped by someone who knows what they're doing. Otherwise, you could possibly end up deleting vital windows components therefore rendering your Computer pretty much useless, forcing you to re-install Windows, which wipes your hard drive.
Not fun.
