I'm asked about the accessibility features at schools all the time. Here's the link that explains the features built in to Windows 7:
Microsoft Narrator is OK for temporary use. I , my students and friends prefer JAWS, but when you are borrowing someones computer MS Narrator is fine.
All y students with stargard's and albinism who need contrast adjustments should know how to change the contrast at school. Their teachers should know that they need to adjust the view and/or contrast for low vision at school.