Calibre

Hi
I am lyinking, but only in name or should that be mane !
My problem that needs a fix. When I down loaded Calibre for the first time I added the wrong e book, Kindle ... should have been Sony any realised this after I had moved to the next window
Please tell me how I can change back to Sony
Tried uninstalling and re-installing Calibre but nae good
Looking forward to some replys
Thanks..lyinking