I have one airport express and both my Mac and my partner's pc using XP Pro can use it to access the internet wirelessly with no problems. However I want to network our computers so we can exchange files with each other. When I click on Network in the Finder I see his pc (chingsim) but every time I hit the connect button I get this stupid error message (screen shot below). So I try to "fix alias" but it asks me to choose a location I would like chingsim to access, when I do this nothing happens and I am still unable to network both our computers. Any advice would be great thanks.