May 2015
I have already played the Sims 3 on this PC and i tried to redownload it and it won't let e says the Product Code has already been used. Well i used it and not sure on what account?
May 2015
if your not sure for which account contact CS for lost/forgotten/merge accounts
http://help.ea.com/en/article/contact-ea-help/
http://help.ea.com/en/contact-us/new/
For Origin
You don't need to re-register again. Simply login with your Origin account from the desktop shortcut of origin the origin you download with the email and password you use for your account my games tab right click the game icon download If it's not there anymore, contact a game adviser
https://www.origin.com/en-us/download
Installation window installing/reinstalling via disks contact CS