Microsoft software for Windows 1.0
Microsoft chose not to port its most popular applications to Windows 1.0. Word for Windows was released in 1989, Excel in 1987, and they both ran exclusively on Windows 2.0 or later. Multiplan, Chart, Access (the communicaions program, not the database one), etc. were never ported to Windows. Neither were Microsoft's various development tools and languages (aside from those that were part of the official Windows 1.0 SDK). Microsoft Mouse was meant for DOS only anyway, as Windows had its own driver model.
I believe the most likely reason for this is Microsoft's rather delicate relationship with Apple. Word and Excel were developed for the Macintosh first, which initially badly needed applications to succeed. In order to develop them, Microsoft was allowed some internal insight into the Macintosh and its software. Releasing Windows ports of their apps so soon could jeopardize their contract with Apple, especially considering all the similarities between Windows and Mac OS (which later resulted in a lawsuit by Apple anyway).
However, since Windows 1.0 had decent support for DOS applications, this wasn't of critical importance. Users could still run DOS programs under Windows 1.0, many of them even in a window, allowing for easy multitasking with native Windows applications. Still, this decision probably had at least some negative impact on Windows 1.0 sales.
One notable exception was Microsoft's demonstration program for their first CD-ROM conference in 1986. It was a multimedia encyclopedia with text, photos, sounds and animations. But the product was not announced for general release, though attendees recieved the demo disc, apparently. A year later, the first version of Microsoft Bookshelf, this time for DOS rather than Windows, was announced at the same conference.