In 1989 , after Apple sued Microsoft for copyright infringement of its Macintosh user interface in Windows , Xerox filed a similar lawsuit against Apple ; however , it was thrown out because a three year statute of limitations had passed .
In 1989 , after Apple sued Microsoft for copyright infringement of its Macintosh user interface in Windows , Xerox filed a similar lawsuit against Apple . 
 However , this suit was thrown out , not on substantive but on procedural grounds , because a three year statute of limitations had passed .