re-installing broadband

My girlfriend has Tiscali broadband. It was a nightmare to set up a month or so ago but I managed eventually.It is a wi fi router.

It has not been possible for other users to log on to the service for some reason. All that happens when you try is that you get a message of the sort 'it doesn't work'. Very helpful.

Since my girlfriend got a new flatmate recently I unwisely decided to try and fix this problem. Tiscali's website said something vague about checking your firewall settings. So I removed both the Window's firewall and the router firewall (login in to the router as administrator). It didn't work (flatmate still couldn't log on), so I put the firewall's back up. Now it is not possible to log on with the primary laptop anymore when the firewalls are up. I fiddled around some more (can't remember what I did now) with the next result that I can connect to the router (even when firewalls are up) but the router can't connect to the internet (when you look at the network settings the link between the computer and the router is fine, and you are shown as connected, but the link between the router and the globe has a cross on it. Window's helpfully suggested that it might have to do with 'domain name s...'.

I have tried everything I and my friends can think of. This includes switching off and uplugging router for an hour before trying again. I have also tried to set up a new connection. Lastly I tried to reinstall the router, the idea being that if I did this maybe the Tiscali CD would automatically find the ISP. After doing this I can no longer connect to the router; basically the same problem that the flatmate had (and has).

Any help much appreciated.

Most routers have a "reset to factory presets" button somewhere, normally something that you have to use a pin to hit, and you tend to have to hold it in for 30 seconds. This will restore your router to its out of the box settings. You can start again then.