You mean commercializing and monetizing code (DOS) that was written and paid for by a client (IBM), without paying them royalties (lost a lawsuit over it), wrapping it in a gui concept that you "borrowed" line for line from somebody else (Apple) without paying for it (lost multiple lawsuits over it), using a name that had already been licensed by another company to describe a gui-interfaced operation system (bought out the company in lieu of losing the lawsuit, changed the name of the operation end to MS-DOS Executive to wait out the legal issues) and then paid off the original copyright holder to avoid yet another lawsuit...

this was NOT "illegally inventing Windows"