As eric said, you shouldnt need the cd at all to configure the router, and should have been able to directly access it, Ive no idea why this made any difference either.
A router is a stand alone mini computer with its own processor and even some memory so you should be able to access direct over the lan from your PC using the following link
http://192.168.1.254 >> Of course I could use that for my mobile??
If you mean use your adsl connection rather than 3G to access the internet... then yes you can... it can be used for phone and i-devices.
I do this a lot as it can save a heck of a lot of data usage if you are downloading to or uploading stuff from your phone/i-device.
I dont know what mobile device you have, but this should be easy to do.. I only mention the 'should' because some HTC devices seem to have problems connecting via wi-fi. HTC are aware of the issue, apparently some models have an upgrade available to correct this, but despite being up to date with firmware, I still see problems with some routers with my HTC Desire S. Other phones/devices should be fine.
If you are worried about wifi security, then most routers can be configured to allow only that device to connect that you authorise. It can take a wee bit longer to first set up, because you have to physically go into the router settings to allow that one device.. but it means that other devices cant connect without your permission first.
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It would be interesting to see some line stats from the new router.