Vista and XP network compatability

I have a desktop with Vista, hardwired to a Linksys router. My Dell laptop
has windows XP and wirelessly connected to the router. Neither computer seems
to recognize the other. I also have an HP printer USB wired to the desktop.
I'm trying to create a network mainly to share the printer with the laptop,
but also file sharing. Both computers share the workgroup name "MSHOME" and I
followed the protocol on both computers to establish a network, but still not
working. Thanks for any help.
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pmcd404