when you turn the machine on, do you see a message like 'press F12 for setup' or something like that?
sometimes it's the 'Del' key, sometimes it's F1...i don't know right now what it is for your particular machine.
once you are in the bios, you will see several pages - go through them all, until you see something relating to 'onboard graphics' that will allow you to enable your 4550 chip.
i'm sorry i don't know the exact setting as all bioses are different. i could possibly help more if you could tell me the exact model number of your laptop.
it may not even be this problem anyway - just an idea...