Like most people, I must use multiple computing platforms (Windows 2000/XP and OS 9/X). While most modern OS's have at least somewhat similar user interfaces, there are always differences. Some are perfectly fine, while others can get kinda annoying. Personally, my biggest problem with Windows is the way in which you use the mouse to highlight text. In OS X, one click = nearest letter, two click = nearest word, three click = entire sentence/paragraph. On windows, you do not have the 3-click option, and it annoys me to no end, as I am constantly copying and pasting text at work (college library). So, what is your biggest peave about going from one OS to another. It can be big, it can be small, it can be completely crazy, but what is it?