I agree that when you're very familiar with the control panel, it's frustrating to have to adapt to the non-classic categorised view. However there are clear advantages to some changes, and I would argue that the Windows control panel is more usable now than it has been in the past. The large directory of icons with no clear grouping by function is a user interface nightmare, and it's only because we're familiar with it that we can navigate it.
And for reference, if you go to the control panel in Windows 7, "Uninstall a program" is right there on the bottom left. If you want to install a program (like IIS), clicking "Programs" takes you to a convenient menu that lets you "Turn Windows features on or off".
It's not quite how it was, but it's actually more intuitive. I'd imagine that you learned the old way of doing it by trial and error. The new system makes that process easier.