Uh, you didn't 're-load' anything. Aurora is a live DB game - any change you make is saved to the database as soon as you make it. The only way to 'go back' is to save a copy of the database in some other location or under some other name. The only way to 're-load' the game is to delete your current copy of the database, and replace it with a previously saved copy. It sounds like all you did was stop the game, then start it up again. Nothing actually changed when you did so.
As for 'Vanquished', it's one of the political states a colony can have. Vanquished, conquered, occupied, surrendered, Imperial, etc. are all names for a series of penalties to the production, research, mining, wealth, etc, of a colony. Over time (dependant on your ground troops' Police Strength (defense strength) versus the population's Occupation Strength (size & Racial Militancy - and possibly Racial Determination & Xenophobia) the status will improve (ie the penalties will drop) until the colony becomes a full Imperial Population.