trying to back up iphone 4s( which has no WIFi) using notebook that dosn't show devices under file? ote book that dose not show devices in the

Trying to back up iphone 4s( which has no WIFi) using notebook that dosn't show devices under file in the itunes ? I am taking phone to genius bar but need to back up info on phone first. The store will not do this as its a privacy issue. Only thing I can think of is taking in lap top and getting them to do it for me unless my lap top is too old .have installed latest itunes on it. thanks for any ideas .