Cannot connect to wireless at home - Apple Time Capsule

I just got a Dell Studio and was able to connect to the wireless network at my university. However, at home, I am having no luck. I keep getting an error message that my passphrase is incorrect. But I know what my network is named and the passphrase. I am using an Apple Time Capsule as my airport -- we are a divided household. I have downloaded the airport software and think I am able to find & connect to my network under the unnamed network choice. But something stops me from actually connecting. Any ideas? Is this a Mac or PC issue? Help!