I have a home network of three computers networked via a Belkin FSD7632 ADSL wired/wireless router. All three have Windows XPSP2.
I have just installed BitDefender Antivirus Plus v10 on two of the PCs. The third is running AVG free + firewall. When we click My Network Places, our computers can no longer see each other's shared files. 
I know it's a firewall configuration problem because when I disable the firewalls, they reappear. Can somebody please give me step by step instructions on how to configure the firewalls to allow file and printer sharing?
When I used Trend Micro on all three computers I had to allow NetBios In/Out but I don't know how to do that on BitDefender. I've tried the user manual but I couldn't figure out what to click on etc... 
If you're answer is really helpful my husband might even be persuaded to buy BitDefender for his PC and laptop but while I'm waiting for him to do that, if you have any hints on what I should tweak on his AVG firewall so I can see his computer on the network as well... I'd be very grateful. 