uninstall the graphics drivers
and reinstall them, that would be the easyist way to achieve what your after.
while editing a file can be done it's not something i would recommend as a good idea, as you may end up having to reinstall the drivers anyway.
the reason why windows remembers the position is pretty simple really, it logs things like resolution settings for cleartype/hue/saturation and so forth as these can be indepently adjusted for each monitor, as your task bar can be dragged around as well as widgets windows will always try to put things in the same place you left them.
if it didn't do that i'd get alot more phone calls from the more stupid side of society at work from screaming idiots crying over things being different every day.