In the original Windows XP version there was no option to change font in the candidate list in MS Chinese input method, especially the Taiwanese one and the fonts there are really small. Sooner or later your eyes start to hurt.
For remedy, download and install TINTSETP.MSI from Microsoft Office IME 2003. Reboot.
Then right click on the language bar > Settings… > select Chinese (Traditional) > click Properties > and select Large font in the Candidate list combo.