Vista-XP network misery. Can anyone help?

OK, I bet you see fifty of these every week, but humor me on this,
'cause I'm tearing my hair out.

I'm trying to set up a wireless network. The Linksys router connects
directly to the desktop, which is running XP Professional. The remote
computer, a laptop, is running Vista. As things stand, both computers
can use the Internet; the laptop can "see" the files on the Desktop
over the network, but not vice versa. The XP Desktop doesn't even show
the Laptop on the network. No matter what I do, I can't get printer
sharing to work.

To sum up:

Desktop: Windows XP Professional
Laptop: Windows Vista Home
Linksys router
Avast anti-virus, Windows firewall

What am I missing here? What do I have to do to get file and printer
sharing working properly, in both directions? I've set up networks
before with no problems, but this one has me stumped.

All help gratefully received.

 

The only way that I can get my Xp machine to be able to access
anything on my Vista machine is to make sure that all the accounts on
each macine are mirrired on the other machine and that the passwords
on one machine are the same as on the other. As soon as I di that all
problems ceased.
Bill Lord
I've taken a vow of poverty To annoy me send money

e-mail messages to bill dot lord at uku dot co dot uk
( Get rid of the spaces and use symbols for the hyphen at and dots )

 

I can't even get the network itself to show up on the XP Network
Connections screen. At my wit's end here.