Windows 7: IP changing

Now it seems that the wireless network doesn't want to work. This is a screenshot of the computer I work. It has wired and wireless connection, but only the wired connection works now.
And on the laptops that use wireless the same problem appeared.

The wireless problem can probably be fixed by disabling/reenabling the adapter from Change Adapter Settings (2nd screenshot you posted left hand side) If it was working before, the DCHP request probably just timed out. Also... you really shouldn't have both wired and wireless going on the same machine under normal circumstances. (Although I understand this was just because the wireless wasn't working.)

I think you may have misunderstood my request, I would also like to see a ipconfig /all from a machine in the 192.168.*.* IP range. Specifically I'm interested in the "Default gateway" that's the easiest way to determine where the original problem lies.

I'm going to assume a basic level of networking here (which you obviously have), so, are the IP addresses of the switches/routers etc. all outside the DCHP pool range? That can also lead to that last error. Especially if the wireless is trying to connect to a different router (probably the problem router) than the wired, which I think is what has happened.

Looking at that screenshot;

1) The wireless connection wont work because its not getting an ip from the dhcp server (169.. address which is APIPA automatic addressing). Also default gateway is blank. In short wireless ip settings are messed up.

2) The wired has default gateway and dhcp server 20.1.1.1.

3) The subnet masks are making me a bit jittery.

I understand your request but I didn't have time to look for a computer with that IP. (because I'm at work right now and I have to fix other problems).

Fair enough I wasn't badgering you, just a friendly reminder... you'd be surprised how many people miss out vital information. It becomes force of habit to repeat yourself.

Can I just ask, how large is this network? How many machines are using it? Just so we can get an idea of the scale of the problem.

I know what you are saying, and you're right.

I can't give an exact number of the machines. About 100-150 machines.

I've used on my computer both wired and wireless on the same time. After I came from vacantion I had only problems here.
I also tried to disable and after that enable the network card and nothing.
The IP's should be like this :
20.1.1.x or 20.1.2.x, or 20.1.3.x
The gateway 20.1.1.1
And I also have the DNS IP.

This info I have from the IT Specialist of the company who is not here right now and I can't contact him. He told me some general things before he left. And now is my job to fix the problem.

Another problem is that in the server room is total disaster, because I don't know where all the cables are going, I don't know the physical location of some equipement (switch, router, AP) and probably I should start with this.... Or maybe this is not related to my problem?

I don't have to many knowledges regarding networking, so that's why I'm asking you.

Also, I must thank you for the patience that you have with me...

Bogd4n, we cant see the server room either. Its difficult if you've been left holding the baby but TBH no matter how much advice we keep giving, it wont help if you dont know the network architecture there or which cable goes where. I would also suggest caution- fiddling around may create bigger disasters than the one you have right now. Best thing to do would be to get the IT man back or at least someone who's familiar with this kind of work. If your job's on the line here, tough luck.

I'm with Bill on this one. Leave well alone. I think in this case we would probably be doing more harm than good by attempting to help.

As we can't see what is going on, and you yourself admit that you don't have much knowledge of networking, any advice we can give you will probably be unhelpful, as in these cases it's kind of difficult not to get technical, even if we could get to the root of the problem (and I suspect you have a couple of problems at least).

As much as I hate to leave you hanging, in this case... I think it's for the best.

I can't leave the problem like that. I must fix it. I hope I'll get in contact with the IT man (he's in Korea, I'm in Romania )

Anyway, thank you guys for trying to help me and for the patience you had with me. I appreciate that. I will let you know how I fix the problem, when I will fix it.

P.S: Sorry for my english; I know that is not very good and I don't get mind if you correct my spelling.

Hello again guys.
Let me tell you how I fixed the problem, or at least I hope I fixed it.
After a few days that I asked you for help, we had here a power down so, all the routers and switches were restarted when we had power again. After that I have found one computer that had the IP 192.168.1.x, so I input the 192.168.1.1 IP in the browser, I guessed the password and managed to access the router interface. I set the DHCP Server option to Disable. I think this is what I should have done from the begining.

Thanks again guys for your help.