But as I said, first try connecting a laptop directly to the router via ethernet cable (set the laptop to auto-detect its IP address). Don't even connect the Virgin cable F-connector yet. Then see if you can access and configure to the address you want.
I guess the router itself might be restricting its settings to valid LAN addresses (of which 100.x.x.x is not) to avoid clashes with the rest of the internet. Try something obvious first (maybe 192.168.1.1) to make sure the technique is working at all, then try another valid LAN address (say 172.16.1.1 or 10.1.1.1) and see where the problem occurs. Probably obvious, but do remember to reboot the laptop after each completed attempt to see what new address it picks up.
Hi Eddie, it is very nice of you posting this solution for ip change. I have tried few times changing mine, but getting the same problems each time. Although, my getaway address change to 192.168.1.1 I am still getting ip address for the computer 192.168.0.10. That zero there is my problem, it should be one.I have also tried restarting router and computer but it does not help. The router somehow forgets the new 192.168.1.1 and gets something like 18.104.22.168. I hope you or someone else who experienced same problems could help here. Thanks in advance..
As dmcfarlane said it seems like this method no longer works. I've lost got knows how many hours trying to get this to work and have only got as far as you describe - the router changes to 192.168.1.1 but keeps assigning my machines a 192.168.0.x address.
If I self assign an address in the same subnet as the router I can get to the internet but I don't want to have to give all my machines and any visitors self-assigned IP addresses.
The ability to change these ranges has been found on virtually every router ever made, right down to the cheapest rubbish from the first days of ADSL. It's completely unacceptable that we're forced to spend money to make up for the lack of such a basic feature given how much their broadband costs.