Where to find driver for gma 4500mhd for vista -acer aspire 5735z(4774)?

i just put windows vista on this acer aspire 5735z(4774) laptop i bought used without a os... i have been able to locate all the drivers i need except the video driver i guess vista put a basic driver on this computer but i want the right driver soo i can get the correct resoulution ... if you could post a link on where to download the driver that would be great