Jesup Hall
From Willipedia
Jesup is home to Williams' OIT Department. It is open 24 hours a day, with card access outside of regular business hours. There you can use computers and print whenever you want to, and chat with the SMCs. The student support desk is located right as you enter; you can bring your computer to them, and they will fix it, like magic.
A great source of information about Jesup Hall is available at the Jesup Hall page on the College Archives Building History site.