I am having a terrible time sharing a printer.  This is my set-up.  My
main computer is a desktop running XP, connected to the internet thru a
2 wire modem.  It is connected by ethernet to the 2 wire and the
printer (LexmarkZ) by USB.
The second computer is a laptop connected to the internet by an
internal wireless adapter.

I have run the home network wizard more times than I can count.  I am
able to ping the desktop from the laptop.  I cannot however ping the
laptop from the desktop.

What am I doing wrong?  I just know it is something simple, but I can't
figure it out!  

TIA for any help!

Michele