I recently got a new laptop with built-in wireless. Now when I first tried using it to connect to my wireless router, it worked fine ... then I joined the workgroup (used by my desktop and old laptop) and started having problems. Why that would make a difference, I don't know ... in any case, I've tried changing it back, with no affect. What I'm getting is very limited internet access - I can ping web sites, but I can't browse to them. I can send e-mail, but I can't receive (although I can determine the number of messages waiting to download). I can browse to my desktop, but only some of the shares will open. My desktop has no problems hitting the internet (or even browsing to my new laptop). My old laptop can also access the internet using wireless without a problem. So I don't think it's a problem with the router ... On the other hand, if I use a wired connection with my new laptop, that works fine too - so it doesn't seem like it's an IE setting either ... Any ideas?

Well, it appears to be a compatibility issue. I just turned the built-in wireless off, plugged in the wireless card (from my old laptop), and now it's working ... although that doesn't explain why it worked the first time! Anyway, if anyone has any tips on getting the built-in wireless working, I'd obviously prefer to use that! The built-in is using an "Intel PRO/Wireless 2915ABG" and the router is a "Dell TrueMobile 2300"

Check the CP/IP setting for your built-in wireless adapter. If it's set to use a "fixed" IP address that could be your problem: Another device is trying to use that IP Address and it's screwing up your connection. When you installed the wireless card from the old laptop WinXP automatically setup a new connection with its own TCP/IP settingss...and the default is "Assign IP Address Automatically" and "Use DHCP Server for WINS resolution" - which is how it SHOULD be configured in a client/server network.

No, the built-in wireless is all set to automatic. Plus I've tried uninstalling it and letting windows auto-detect it again. So everything would be back to the defaults (if it wasn't before).