home network problem

network magic and linksys neither can help me. from my desktop i can access my shared files on my laptop but not vice versa. and i cant get any help from anyone. i followed their instructions to the letter. if anyone wants to see the responses i got from both of them,email me at oldmantoo49@hotmail.com. i need help. is there a network diagnostic program that i can use to fix network problems? please reply,please. and what is comondo?