I have a Cisco 877w router that I have reset. After trying a lot of different Java versions for the configuration applet (turns out the router uses a deprecated certificate that has been removed from latest Java versions - I got it working with Java 6 update 16) I finally got the Cisco SDM Express Wizard running.
After going through Overview -> Basic configuration -> LAN IP Address -> DHCP I should continue to the next section, Internet (WAN), but when I click the Next button nothing happens and the wizard is stuck.
I do not have the router connected to an ADSL cable as I was hoping to be able to use one of the ethernet ports for WAN and the rest for LAN. If that is what is causing trouble I can instead use the telnet interface to configure the router, but I prefer the GUI.