I had been using Windows smart phones/PDAs long before smart phone became popular. I got my Windows 7 phone on the first day it became available. However, it was a piece of junk in terms of software (hardware was fine), much worse than version 6.5 that it was supposed to replace. As a result, I returned my new phone after 2 weeks.
Since then, Windows phone share dropped from something like 30% down to barely above 0%.
How to increase market share for Windows phone and tablet? The answer is simple: make Windows phone and tablet run on the full version of Windows. Today's phone (quad core running at more than 2GHz) should be powerful enough to run the full Windows operating system. To save space and power, Microsoft should be able to delete some functions, but make phone capable running regular Windows programs.
Customers have already shown that they want Windows tablets running full Windows, not Windows RT. If a Windows phone can do the same thing, it will be very cool: when traveling, all you need to bring is your phone, with a bluetooth keyboard and mouse, with video port capable for connecting to a projector (this is possible already for some phones).