I have a Sonicwall TZ100-N wireless UTM Firewall. I've configured wireless access on it for the users using the built in wizard. There is a Server 2008 Standard box that is the DHCP server. For some unknown reason clients can't connect. I can get a few iPhones and iPads to connect, however a few Windows 7 and Windows XP machines can't. Some Windows XP boxes can't even see the network. Some Windows 7 boxes can see it full strength however it says "Windows was unable to join the wireless network". I'm looking for a quick 'Best Practices' or 'How To Guide' to make sure I've probably configured the Sonicwall with the DHCP etc.