XPer wrote:
My Win XP Home laptop has lost connectivity with my home LAN.
AT&T installed a replacement modem. Other devices made the proper hookup.

My laptop says it is connected and say it is an excellent connection but
it will not connect to the internet or to my Buffalo NAS that my other
desktop windows PC connects to without any hesitation.

Browsers do not work. Chrome say it cannot connect. As does Firefox.

Strangely my Buffalo NAS app finds the NAS but says it probably will not
work as it has a limited connectivity.

What does that mean ?

Please offer steps to troubleshoot.

Have you manually assigned an IP address on the laptop ?

Or are you relying on the automated DHCP settings ?

The "obtain an OP address automatically" here, is the DHCP choice, the default.

https://it.ubc.ca/services/email-voi...and-windows-xp

*******

In Command Prompt, you can do

ipconfig

and the IP address should be listed. You can compare that
to addresses used for your other equipment.

Since the laptop says it's connected and is excellent,
then the ipconfig should have an IP address you can examine.

Paul