Windows Vista/XP Fonts Appear Broken and Rough Looking
I came across this today when I was looking at a website I was working on with another computer to my own. It was a Windows XP machine. I found the fonts very broken and pixel-ee(?) At first I though that it could be a problem with the fonts that are installed on the machine. But the font versions were the same. The problem was just a small performance tweak in Windows XP and Vista which turns off the "Smoothing of screen fonts". Here is how it can be fixed:
1. Go to "Run..." in the Start Menu and type in "sysdm.cpl" then click OK. A new window will open.
2. In this window select the "Advanced" tab and under "Performance" click the button titled "Settings". A new window will open.
3. In the "Visual Effects" tab select the "Custom:" option and scroll down the list to make sure "Smooth edges of screen fonts" is checked.
4.Click OK, Click OK.
5.Reload whatever page you are viewing in your browser and fonts should now be smoother and looking nice.
Hope this helps.

