can't connect xbmc to home network

I was previously using winxp pro and had no problems streaming movies and music to my xbox. I since reformatted my computer to win7 ultimate. I managed to find both of my win7 pcs through xbmc , trying to create a network path the my shared folders, now Im stuck at this smb lock screen, Ive put in every password and username I can think of but nothing works, any ideas?

thanks for your time

N0_0ne