Besides MS-Dos not being similar to Apple BASIC, MS did not steal anything from Apple as so many Appletons would have people believe the US Courts have backed that up.
“Apple Computer, Inc. v. Microsoft Corporation, 35 F.3d 1435 (9th Cir. 1994) was a copyright infringement lawsuit in which Apple Computer, Inc. (now Apple Inc.) sought to prevent Microsoft Corporation and Hewlett-Packard from using visual graphical user interface (GUI) elements that were similar to those in Apple’s Lisa and Macintosh operating systems. The court ruled that, “Apple cannot get patent-like protection for the idea of a graphical user interface, or the idea of a desktop metaphor [under copyright law]...”[1] Because Mac’s GUI was heavily based on unlicensed GUI developed before by Xerox,[citation needed] in the midst of the Apple v. Microsoft lawsuit, Xerox also sued Apple on the same grounds.[2] The lawsuit was dismissed because Xerox had waited too long to file suit, and the statute of limitations had expired.[citation needed] Apple lost all claims in the suit except for the ruling that the trash can icon and file folder icons from Hewlett-Packard’s NewWave windows application were infringing. The lawsuit was filed in 1988 and lasted four years; the decision was affirmed on appeal in 1994[1], and Apple’s appeal to the U.S. Supreme Court was denied.”
Basically, the court ruled is was not stolen because of no patent - not that it was not actually stolen.