>>If your wireless router has been running for a long time without a reboot, you might try rebooting it. Could you confirm (maybe with another wireless laptop) that your router is OK?
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>>Assuming your router is OK, maybe you could borrow an external USB wireless adapter, plug that into your laptop and see if you can get on the internet with that.
>
>I did a test like that earlier on today. I removed the plug for about 10 seconds and restarted everything. Is there any other way to have a better reset? ...such as an option in the interface?

IIRC you have a Linksys wireless router. No, there is no better way to reset/reboot those devices. There is a "factory reset" option but I'd advise against using that, you'd lose all your custom settings and likely wouldn't help anyways.

Did you end up upgrading to 3rd party firmware such as dd-WRT? I've had extremely good success with all my clients using v23 SP2, none have ever had a router problem with that.