I believe that the main UI font for Windows XP is Tahoma, but if you're building UI, you should use MS Shell Dlg2 (there may be a space before the 2) since that's a virtual font that will be changed ...

Windows only: If there's only a few things most Microsoft Vista upgraders and naysayers can agree upon, one likely talking point is that Vista's fonts are generally clean, smooth, and a step up from ...