Problems connecting to Wireless

Hello, looking for some help please - I'm sure it's pretty simple but I have googled it and I really don't understand the answers as they are very technical and my knowledge on these things is very minimal! Hoping somebody can put it into English, easy to follow steps...?!

I have a Macbook Pro and after being away at work all week I have come back and cannot connect to an open wireless network which I usually use, still in the process of getting my own secure broadband to use.

My airport is on, I try to connect and the wirless symbol has an exclamation mark on it, I open network preferences and it says the airport has a self assigned IP address 169.254.etc and will not be able to connect to the internet. I click 'assist me' and my network diagnostics pop up, the network settings circle is yellow and the internet and server are red, the airport, airport settings and ISP are all green.

Sorry if this has come up before, I just don't understand the answers most people give as I haven't the slightest clue about these things! Would anybody please be able to help me in basic english?!

Thank you - help v. much appreciated as lots of work to do over the weekend!

When you click on your wireless icon and click on join other network does it show the
network in question and what happens if you click on it ?

Yes, it shows a range of netoworks both open and closed. The network I use whilst I am waiting for my own broadband is there as an option, when I click it an exclamation mark appears on the icon and in the network box it states that my airport has a self-assigned IP address and will not be able to connect to the internet.

Ok 169 is a default for just about everything that cannot get an ip so in network in advanced in system preferences TCP/IP set configure IPv4 using DHCP you may also have to hit renew lease. I don't really understand why it would not auto connect you still may have a wireless card issue does it connect at work without problems wirelessly?

Thanks, It was already set on using dhcp and even after hitting new release the ipv4 is still 169.254.etc and unable to connect. Yes I was away during the week and it connected fine to the hotels wireless, it's just happened since I have returned home.

Try this: in the advanced settings of "network" it will show a list of every network you've connected to lately. Try deleting the one you are trying to connect to now, and THEN try to connect to it anew (as if for the first time).

Also, if you have your software firewall turned on, turn it off (and keep it off).

Hi - thanks for your suggestion but it's still coming up with the same problems even after I delete the network and try to join as if new. Not too sure how to change the firewall? Would resetting it to factory setting work, and would this delete everything I have on there; work, photos, installations etc.? I assume as it's the network settings which has the 'yellow' light next to it in network preferences, that there is something wrong there. Is there a way I can enter a manual IP? thanks again for all suggestions, very frustrating!

Have you run Network Diagnostics?

The Firewall is off by default, but if you have it turned on you can turn it off by going to system preferences, Security and turning it off there.

What is happening is pretty simple. The network you are trying to join is not assigning an IP address to your Mac. Odds are the networks admin has assigned some sore of security to the network that your Mac doesn't like or there is a firewall enabled on the router itself that is blocking you. You need to to contact the owner and find out what if any changes they have made to their router that is causing this issue.

Thank you both - turning firewall off didn't help so I assume baggss you are right and the network admin has done something so that I/others cannot get on. Hopefully will be able to connect when I head back to work and will try get internet for my apartment sorted asap!