Dell Inspiron 1545 Problems

i have a dell inspiron 1545 3gb ram , 160gb hard , 32bit operation system

i had windows vista home premium installed in ma system but i didn't like it so i installed windows 7 32bit in my system , it works fine but most of my laptop's functions wont work on it , like when i turn down my laptop's volume it doesn't show me in the display but it works , same with the brightness and wlan switch button, they all work perfectly fine but without any screen display , it used to come with the display on windows vista and i had a webcam studio installed in ma laptop with windows vista that allowed me to take pictures and record videos through ma webcam and save them on my pc ,

does windows 7 has any webcam software like this ? one more thing ,my webcam wont work with my msn live messenger, i works fine with yahoo messenger or on facebook an Internet ,when i try it on my msn it says'' messenger's not ready for webcam try again later' i tried everything uninstalling webcam driver and msn messenger but nothing worked.