Do your eyes a favor, use Clear Type Fonts

ClearType delivers improved font display quality over traditional forms of font smoothing or anti-aliasing. ClearType improves readability on color LCD displays with a digital interface, such as those in laptops and high-quality flat panel displays. Windows XP comes equipped with it and you can change the setting to use Clear Type fonts. Windows Vista has Clear Types enabled by default.

To enable Clear Type:

1. Right click on a blank area of the Desktop and choose [Properties]
2. Click on the Appearance Tab; Click Effects
3. Check the box: Use the following method to smooth edges of screen fonts
4. In the drop down box select: Clear Type 

To change the Welcome (logon) screen to use Clear Type:

1. Open the registry editor and navigate to: HKEY_USERS\.DEFAULT\Control Panel\Desktop
2. Create a new String value (REG_SZ, REG_DWORD), or modify the existing value, called
"FontSmoothing" and set it according to the value data: 0=disabled, 1=standard, 2=ClearType
3. Exit the registry; you may need to restart or log out of Windows for the change to take effect.