My PC is on the CAMPUS network and installed XP professional with all security updates. I have a problem with my network thus I can access to my friend PC but my friend cant access my PC.

I dont on my firewall and I dont know why. While my friend access to my PC, keep asking the password. He is using WIN ME. ANd after I type my password, still got problem saying that the password is not regonized.

Any experience before? is it bcoz of the security update I installed?

Thanks