Trouble with Live chatting

I have tried with two external mic... both web cam and a microphone, and the problem remains with both.... I dont think my computer has an internal mic. Thank u for ur quick respons :))

again... thanks for ur help. I'm a little hopeless when it comes to computers. I'm sorry to say that i am still having issues with live chatting. Now i have gone to the "controllpanel"  for testing of the soundsystem. Here i get to talk into the mic and hear it beeing played back. Unfortunably I too hear the horrible sound, which is extremly loud and uncomfable (and it is not my voice ;) ) I think i might reboot the whole computersystem to see if it works... do u know if that is very complicated?????