Interesting networking problem

This may sound kind of unusual. But about 2 months ago everything worked perfectly, then I left town for a couple months and when I got back the internet seemed fine for the majority of the time.

However, I've been experiencing several difficulties that one might expect from a firewall, but in my case, I don't have a firewall. Here's the problem. When I try to send files over say MSN Instant Messenger it won't work, but I can recieve files. I can't start up a net meeting with friends and such. Also, with mIRC the Identd server won't work even though it's enabled. It's almost as if that I can connect to computers, but they can't connect to me.

Anybody know how to fix this problem?

 

What OS?

 

Remove and re-install TCP/IP.

release and renew ur IP. Try to also update the drivers of the nic - but may not be necessary.

Update Windows.