I've been dealing with this issue for a couple years now. I'm not sure how to eliminate the taskbar programatically- though of course it can be done, as evinced below- but I know of a couple convoluted solutions:
StarDock's "ObjectDock" software: you can pick up a free trial by Googling it. If you set it to start on system startup, make the dock transparent, remove all the icons, and use an empty .ico file as a placeholder (it needs at least one shortcut present, or else it populates the dock itself), this will take care of your taskbar completely in an unobtrusive way (once you go through the trouble of setting it up, that is.) Also, the trial doesn't seem to expire if used in exactly this manner, though you'll get popups nagging you to purchase, which I finally did.
"Dexpot": Dexpot also has a 'remove the taskbar' function, if virtual desktops are your thing. To enable it, install Dexpot, right click on the tray icon, select "configure desktops," go into 'tools' for your particular desktop, and tick "taskbar." This beats the native Windows 'hide the taskbar' feature, but isn't quite as seamless as ObjectDock.
That's the best I've been able to come up with. If I'm able to figure out how to do this with a script, or via the registry, I'll edit my answer and link to the script/registry change.