In 1985, shortly after the release of Windows 1.0, Bill Gates set Min Lee on a mission to find a partner for a digital encyclopedia product that would serve as a reference companion to Microsoft’s productivity applications. Lee then approached Britannica, the undisputed leader in the encyclopedia market, who’d recently released a new version of the fifteenth edition of their encyclopedia. Microsoft proposed a partnership to produce a multimedia CD-ROM version of the Encyclopædia Britannica. In exchange for non-exclusive rights to Britannica’s text, Microsoft would pay Britannica a royalty on each copy of the CD-ROM product sold. Britannica immediately declined Lee’s proposal.
I remember when that was recommended to be used with a 2nd drive as the install root ('cos the primary IDE didn't have the headroom for all the I/O - man, we've come a long way!)