I just hit this same problem with a brand new Win 7 (sp1) + (all windows update) box built just for managing 3D printer builds,...
I was just about to claim that the link above does not solve this particular problem (though i knew i needed that driver) when on a whim (or perhaps out of desperation) i downloaded the older v2.10.00 version,.. guess what, the old one includes one additional needed driver and now everything works as expected!,. SO,. if your having problems with the latest version of the ftdichip install and your on a Win7 build,. try the older v2.10.00 it squashed the error message (code 43) for me =)
you may still get the error message,. if you do, make sure to refresh your com ports in your slicing software, and select the new one that just popped up!