This question already has an answer here:
I can connect to my house's wireless network just fine, but when I'm connected I can't browse the web. Firefox starts connecting to a site and then just poops out. This doesn't happen on my roommates' computers (running Windows) or on our 3DSes, so I know it's just my laptop.
(Edited to remove irrelevant information)
I would post this as an answer, but the site keeps converting it to a comment. Thank you for all the suggestions, though!