Hi harrisgx, welcome to the forums. I apologize for the confusion. The "Desktop Calendar" is a special component which comes in full-sized and mini versions. The Desktop Calendar resides directly on the Windows desktop/background/wallpaper/whatever-you-wanna-call-it. It doesn't behave like a regular window.
The main calendar (aka main window) option IS on the task tray icon menu. It's the first option, labeled "View Calendar". Maybe I should rename this menu option "Show Main Window", to reduce confusion? In any case, selecting that option will show the main window.
For what it's worth, these various components are all explained in detail (I know, nobody reads this stuff):
http://www.vueminder.com/products/vuemi ... indow.html
http://www.vueminder.com/products/vuemi ... endar.html
Some people like the desktop calendar mode because it's always shown on the Windows desktop, and provides quick access to a schedule without needing to open another window. If you don't see the use for the Desktop Calendar, this can be disabled by unchecking the menu option. This is explained in the FAQ:
http://www.vueminder.com/index.php?page ... ing#FAQ303
I hope that clears up the confusion. Please let me know if you have any other questions.