Firewall [ How To Enable]

Hi!!! i am new on BitDefender forum..so i didn't know where to post so forgaive me if that is the wrong place to post sth like that ...anyway...I have the "Bitdefender Antivirus 2009" and for one reason( i don't remember how:( ) the firewall disappeared (maybe i did sth that i didn;t have to ..this happened before 3 days...so I couldn't enable and i use the windows firewall...Now I am not so secure than before...And BitDefender's firewall was more easy to use and it aware me for any programme can hurt my p/c...now i want to tell me how to enable again the firewall.. please use "informal" language because i don't speak very good english..so speak more informal in order to understant what you say...(please write me step by step what to do...I am new at BitDefender) also i use windows Vista home Premium.....................................THANKS for ALL .... please HELP me