Please remember that the PC with WinXP SP2 has Windows Firewall . I suggest
updating the WinXP SP-1 to SP2 and make it fully updated. Please make sure
not to use any other third party Firewall AND Windows Firewall at the same
time. Remember Norton Antivirus 2006 and 2007 can sometimes mess up things.
Are both PCs WinXP Pro or Home? Important to post all these details to get
the best advice from a Newsgroup
Since you have a Belkin 54G wireless router (but not used in wireless mode
probably because of lack of wireless adapters in the PCs , I guess] where
both PCs are now connected through Cat5 Ethernet cables [the cables must be
"Straight -through" and NOT Crossover Cat5s] you must be able to have both
a Homenetwork and ability to access internet independently of each other via
the broadband modem and Boradband ISP.
In the Networksetup Wizard use the 2nd option (.) This Computer connects to
the internet through a "residential gateway" (a 'sophisticated' name for a
"router"!) or another computer on my network .
Then complete the wizard choosing Files and Printer sharing option . Good
luck
CM