I figure it’s only fair to highlight good design as well as bad design, especially where the good design is an improvement over a previous iteration. Here’s my first entry.
When you launch a program in Windows 7 and 8 you get a combo 3D/glow effect on the taskbar icon to let you know the program is running. Multiple instances of the same program stack like cards (as seen by the Chrome and File Explorer icons below):
The problem here is if you have a mix of running and non-running programs, it becomes difficult at a glance to see what is actually running, especially if you only have one instance going.
Windows 10 dispenses with this and instead uses a slim but easily identified white line under any program that is running, like so:
The effect actually looks better than the screenshot depicts (the white line is slightly thicker and brighter) but you can still tell at a glance that File Explorer and iTunes are not running, that Firefox and mIRC are active and that OneNote is the program that currently has focus because of the shading behind its icon. The UI is further clarified by stripping away the 3D glow effect, which creates too much visual clutter. The overall effect is cleaner and more practical. Good job, Microsoft!