SECURITY ALARM!!!

my girlfriend has a 2000 ford escort with a manual tranny, when she is in school she takes the keys out of the car, but the security alarm will go off several times during the day, but if she leaves her keys in the ignition then the car alarm will not go off, she asked me if i would just disconnect it for her so she dosent have to worry about it anymore. i was wondering if i disconnect the security alarm will it mess anything else up, will the car not start or anything like that cause i know those security alarms can be sensitive at times

I APPRECIATE THE HELP AND SO DOES MY GIRLFRIEND :D