Changing NAT to Open (HELP!!)

[Mercy]

so i have cod mw2 and when i just got it my connection was strict and i was able to play ALL games, now that sometime passed my connection is still strict even though my UNPN IS ENABLED, and it WAS ENABLED all the time and i am only able to play team death match and free for all and none of the other 10 or so game mods

i disabled unpn and ebabled it and my connection switched to Open, however i was STILL not able to connect to any of the servers but team dm and free for all

ive looked up some solutions but most of them have xbox live ports and all that stuff i dont get

if you have a solution for the PC, please help me out, or if you know someone or a link to where it shows how to solve it, plzzz help out

[NormandyAlive]

Try this link http://forums.steampowered.com/forums/showthread.php?t=1019454

 

If that doesn't help i donno.

[Cromyth]

I reset my router and it works for me.

[Mercy]

everyone gives me the ports, but i have no idea what to do with them :/

[ReGIONALS]

portforward.com

find mw2 and follow the instructions