Do not know how to connect my PCM to wi-Fi. Windows Vista. Help?

I feel like an idiot because it should be so simple to get the Airport Express to work with my iPad and PCM but my PC just doesn't connect. PC is Windows Vista. Thoughts on what I am missing are so welcome! Been trying to figure it out for weeks. Is it the PC or the connection between the chair and the keyboard!

Thanks so much. Help?