Problem loading software for USB Wireless Adapter

I am using 2 computers running Windows XP Home.
I have just changed from a wired network using a Router to connect to the
Internet, to a Wireless network. 1 computer works fine but I had trouble
loading the USB Wireless Adapter software on the second computer. At the end
of loading the software, I ended up with the following message headed
"Wireless Configuration" - "Notification dll has not been registered, program
will not work correctly". I eventualy forced the the connection to be set up
by starting the Wireless Zero Configuration Service manualy. Every time I
Boot-up I get the warning message and I have to start the Configuration
Service manualy to establish a working network.
Any ideas, please?
Can anyon