Boostedpos

Ive been quietly lurking around here for a little while and im a newwbb so sorry in advance haha. I got the car turboed and on a megasquirt beforehand so i never tuned the car myself. It is a 1990 and the car had ran fine just a little rich so i wanted to fix that and put a tacho output on the ECU. So i hooked up the megasquirt to my laptop using tunerstudio and of course since i never had to tune the car before this is the first time the ECU was being talked to with my computer so i made a new project and had the program detect my ECU and what not. Well i turned on the car and it idles like ****. I always had a mild coldstart but this time it is so fucked up im positive the tune is off. Is There anyway i can reupload the previous tune or do i have to retune it altogether? I dont mind retuning it but id like to have the previous tune for a starting point so i have some kind of reassurance if i **** everything up. Also are you guys using the free version of tunerstudio or is everyone registered?