"I would recommend checking this HowToGeek article on ClearType to tweak your settings and to make it the way you want it to be
Tune Your ClearType Font Settings in Windows Vista
Many people have expressed to me their dislike of the default ClearType font smoothing in Windows Vista, and asked for a way to change the settings to something better. You have a couple of options here:
You can just Disable or Enable ClearType. (Note that if you are still using a CRT monitor, you should not be using ClearType anyway.) Install Microsoft’s ClearType Tuner PowerToy for XP (which works in Vista, even if it says it doesn’t)"