TweakUI, by Microsoft, is a handy user interface to adjust various Windows settings not exposed in the standard XP setup.
Platform: Windows XP
Why Did I Download/Buy This?
I first became exposed to this utility through a Lifehacker article “Boot Windows before you log in”, which gave instructions on how you can start Windows (and all associated devices, etc) before you log in. Since I have several necessary devices and services that slow down booting, this hack was something very useful.
How Do I Use This?
After I downloaded TweakUI, I began to look at the other settings in this software. I use it to keep applications from stealing focus (you know, pop-ups that come up while you are typing and you lose your chain of thought); I changed the shortcut arrow to be less glaring; I changed the colors of file types to make them more distinguishable; I reduced the size of thumbnails; disabled autoplay on a lot of drives; and changed around some drive letters.
There is a lot more that can be done with this utility. I suggest you download it and play with it!