Compaq Presario C500(C552US) LCD Problem....

[DamnRena]

well this initially came with visa basic installed and i didnt want vista becuase it came with only 512MB of ddr2.....so i wanted to downgrade. So i did and not knowing this was supposed to be for Vista only i ran into many problems. But i got some stuff to work except the sound. I ran in safe mode and installed the sound drivers manually and the system rebooted and now my screen is very very dim and i cant see nothing, well a little if you tilt your screen. When i hook up my LCD monitor to the laptop it works. What problems can this be??? can installing a sound driver manually in safe mode kill my LCD screen? or can this just be the inverter?