Help re wireless connection problems urgent!!

Well, I'm totally new here, and I'm not especialy good with computers, but I've always gotten by completely fine without much problem. I bought a new MacBook pro about three months ago from Apple US, and then I moved to Germany and brought my American computer with me. I also brought my iPod touch. As soon as I tried to connect to the wireless cnnection where I'm living, it wouldn't work on my laptop. I thought it may have something to do with the fact thatall other computers on the network are PCs so I tried my iPod touch and it works fine!
The network is a locked one with a password. It is a wireless LAN connection through a german company called Arcorwireless if that makes any difference. When I turn my laptop on, the wireless network Arcor pops up automatically like it should. If I click on it, it asksfor the pasword which I enter. For a few seconds it appears to be working and says "connecting" and seems to have a connection with the bars in the upper right hand corner but after about 20 seconds it says "connection timed out" I'm really desperate to be able to contact home and getting to an apple store would be a huuge problem. Is there anything I can try?? If anyone has any idea what to do, I would appreciate it beyond belief!
Thanks in advance!

 

Thank you very much for your answer. I did try that and the correct network pops up and I enter the same password all the other computers use and the one I use for my iPod and it thinks for a time and comes up with a screen that tells me the password is incorrect. This can't possibly be true becuase I have entered it for other computers and it will work just right. I entered it multiple times to make sure it isn't a typo. Any more suggestions?
Thanks again!