I just updated to a new computer with 64-bit and Radeon ATI HD4550 video card but the screen image is worse than the previous computer which had a standard intigrated video card. My monitor is a ViewSonic 2450wm 1080p LED and had a awesome image before the upgrade. I have tried everything and spent hours on ATI's Catalyst control center with no resolve. I have reinstalled video drivers, monitor drivers, and anything else I can think of.
What resolution are you running at and what connection are you using to the monitor? You should be at 1920x1080 with 32 bit color, 60hz refresh rate. At that resolution, you don't want to use the VGA cable, use DVI.