Router-TX Rate changed-can't connect

I’ve been using the site for years, and finally joined. It seems like a great forum. I live with a roomate, and he is on vacation. His side of the house is locked, as he is on vacation, and the router is in his place.

Yesterday I was attempting to connect to Xbox Live, and was getting MTU failed. I accessed the router wirelessly, and changed the MTU to 1400 (Xbox Live requires at least 1384) I was still getting MTU failures. I was advised to change the TX Rate to 54 Mbps (obviously wrongly, I should have researched more), it was on Auto. I changed that setting, and now I cannot connect to our network. It is on my list of available networks, but I cannot connect to it at all, in order to change the TX Rate back to Auto. I am able to connect the the network at school fine, so it’s not my PC, it appears to be the router and the TX Rate I changed.

Any ideas how I can access the network? Normally I would just plug into it via ethernet, but I can’t get to it for over 3 weeks when my roomate returns. Thanks for any help you can offer.