Ok, to answer serveal questions...
Setup is indeed, cable modem-wireless router-laptop. Formerly had desktop system simply plugged into router, no wireless ability for the desktop system w/o buying additional stuff. (Damn, maybe I should simply do that to the laptop? Plug it in to the router while disabling the wireless function?)
*edit* tried this, no joy...
No connections bridged and had turned the XP firewall off after it first failed to connect with it running, I do have the XP firewall set to allow OP to access the internet(and yes, have the WINXPSP2)
I did set everything back the was it was, obviously is working correctly, since I'm here and it let me post about the problem to begin with.
Checked IP config commands and all the number match exactly. It does say It's in DMZ mode, including giving me some warning about my network being unprotected. But, since I use ZoneAlarm as well as the WINXP firewall(on both desktop and laptop), not concerned about that.
I did previously disable the wireless connection and re-enabled the Realtek adaptor when I was trying to connect by plugging in the cable modem to the laptop. When I did that, it told me I had limited or no connection...
I also checked the device manager and it showed the X's and ! icons in what appeared to be in all the right places. While I'm not a Computer Techno guru, it did appear as if it was all set correctly. I only saw the "!" icon on the Realtek adaptor after I got the above mentioned message.
When we first got the laptop, I was able to enable the wireless connection with great ease, kind of expected reversing the process to be just as simple.
Also checked my router settings and it is running in DMZ mode. It was my (limited) understanding that this would avoid having to set ports open, etc and that has worked great for online play previously, allowing me to play OP and other games online with no problems at all using the desktop system.
Thanks again for all the help...keep it coming...