Complex sentence: When Microsoft made changes in Windows 2.0, such as overlapping windows and other more Macintosh-like GUI features, Apple filed suit, and then added additional claims to the suit when Microsoft released Windows 3.0.
Split into simpler sentences: When Microsoft made changes in Windows 2.0 adding overlapping windows and other features found in the Macintosh GUI, Apple filed suit. Apple added additional claims to the suit when Microsoft released Windows 3.0.