Ok, then you will need to change the router setup, although your company should have picked something less likely to be in use. the 192.168.1.x and 192.168.0.x are the most commonly used ranges in routers.
Your router should be sitting at 192.168.1.1
Visit that in a browser: http://192.168.1.1
User / Pass should be admin / admin
You'll be looking to change the default network range in the LAN settings.
Pick something that is in the 10.x range if your network is using 192.x
10.0.0.1 for the router ip address should be an ok choice.
You'll need to save the settings, and the router will reboot. If you want to continue changing settings, you'll need to visit the router at the new ip address you set it to.
As information about your router is scarce, and the provider makes you register to look at anything on their site, thats up to you to find out how to do those steps.
Personally I'd toss that heap of junk, and replace it with a better router, and adsl modem.