Quote from Lucrum:
I think I've deleted old settings before, but can some kind soul remind me how?
first step is to find out folder with account settings. just click in TWS on "Restore settings" in TWS. on top there is will be "Look in" with settings folder named something like "dwjfghg". typically located in C:\Jts folder. close TWS and just delete it. next time you start TWS-it will run on default settings