Is your remote key working or do you lock/unlock the car manually?
Copy-and-paste this url for reset procedure-
http://www.programyourkeys.com/Renault_Laguna_II_Key_Remote_Control_Fob_Transponder_Programming.html
Your car probably has the infrared key.
You can get the by-pass code at this site-
http://www.bba-reman.com/content.aspx?content=Test_for_Renault_Key_Immobiliser_failures_emergency_recode
You will have to re-enter the code every time the engine is stopped for more than 15 minutes so it's really only a temporary repair.
More info is available at this site-
http://www.renaultforums.co.uk/
Sign up and use the search function.
Brian.J.
October 2008