No one can connect to me! Help!

No one can directly connect to me, no one can even ping me. For as long as I can remember I've never had any troubles of this sort until I reformatted my computer. I can do everything else fine, I just can't receive connect requests. Windows Firewall is off, and I even set up my DMZ. I'm running my internet through a router, so is there something I need to be setting up in that respect?

I turned off the firewalls on my main computer, set up a static IP for myself and all, and still nothing.

Any help would be greatly appreciated.

Anybody?

Are you doing NAT on the router to the machine?
What service(s) are you trying to connect to?

Yes, I've got NAT set up, and mostly I've tried it with games.  People can't directly connect to a game I host.

Also I'm going router>Switch>My computer.  Not sure if that gets in the way at all, just putting all variables out there.

I did a whole bunch of crap, but it works now.  My MAC address wasn't set up, I think that's the main thing though.  Thanks for the post anyways anon.

how in the holy fuck was your mac address not set up
it's hardware!

MAC address can be spoofed, thought its hard to do! Possible to "hack them" and change them

althought saying that, the knoledge need for that is immense