Don't understand firewall message



Hello Group:
My system:
Router Linksys BEFSX41
Desktop - Win XP Pro SP3 32 bit, Deerfield Visnetic software firewall
Laptop - Win 7 pro 64 bit

Question:
I just bought the laptop,plugged it into the router, and Win 7 set up
the networking without any input from me.
My desktop has an IP address of 162.168.1.151
The two connect just fine.
But now I am constantly getting messages from the firewall on the
desktop about an inbound TCP connection attempt:
Source 192.168.1.100 (? the router or the laptop) on port 50193
Destination: 192.16831.151 (my desktop) on port 445

I would appreciate an explanation of what may be going on, and advice
if I should block or allow it.

Maybe I need to give my laptop an IP address. My old one was XP
machine with IP 192.168.1.152

Many thanks.

Jack

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