Clean install of XP. It'll save you loads of messing around.

You don't know what files are damaged, and they may not just be the 'network files' ones.

Clean install, then focus on the network...

I've not got any experience of them.

Google for 'plus.net complaints' and 'plus.net reviews' - there's not much mention of them at the moment:

http://www.reviewcentre.com/review219190.html

A-ha! So something probably did change.

If it was me, I'd start with a full recovery and go from there. After all, you've no way of knowing what damage/corruption has been done.

Also worth...

If you have a viable DSL connection, then all you have to do is those three things I mentioned: connect the router to the line, connect the computer to the router, then tell the router your account...

First of all, nothing has changed - in theory - on the computer-to-router side of things, so the default gateway address should be the same as it was before. You mentioned 192.168.1.1 - are you...

The DI-624 is just a router not a DSL modem/router. So you'll need a DSL modem - and watch out for those awful USB-powered Voyager things the ISPs usually supply.

The most elegant solution is to...

With only 10 feet and one floor you should have a good signal.

What we'd advise at work is reset the router completely, and make sure that Windows is controlling wireless on the laptop.

Then...

We sometimes get problems like this with customers who call us at work, but I stress that just because someone has similar symptoms it doesn't means it's the same fault... so this is just some...

Hold in the reset button on the back for 15 seconds, let it reboot, and check that all the correct lights are on and are steady (as per the manual). That will make sure the router is set the best it...