Airport Time Capsule unexpected error during wireless connection

I'm trying to connect my time capsule to an existing network but keep getting unexpected error. I want to connect wireless. I had it connected to a created network and this wants me to connect to a router via ethernet cable, and I don't want this. any advise. I tried to set it back to factory defaults I followed all the instructions and it does't seem to reset to factory defaults.

[Re-Titled by Moderator]