Networking problem

[matsm]

I cannot get my desktop computer on the home network, it has been able to connect to the network before, but it was very unstable and not it just does not work at all. My landlord has fixed the issue that made the network unstable and I am able to get my laptop onto the network and so can all my other housemates.

Both laptop and desktop is running Windows 7.
The wireless card I have is Ralink RT61T and the router is NETGEAR(not sure on the exact model but we have tried different once).
I had the desktop over at a mates house over the weekend and I was able to connect to his network with the desktop without any problems.

At home the signal strength varies between 40-60%, my landlord also brought over an extra router and put it next to the desktop so it was 100% signal strength but still would not connect to the wireless, but it did connect with a ethernet cable.(ethernet cable cannot be a permanent solution as all the networking gear is at the house nextdoors)

We have tried different routers, different security settings, even tried disabling all encryption, the hardware firewall making the network naked without any luck.
We tried giving it a static IP, but it wont even shop up in ipconfig.
Tried uninstalling the wireless card and different drivers.
It's like the network receives the wrong mac address but that's been double checked that it the right one.

the network runs on b,g and n and my card supports both b and g.

Any suggestions on what can be tried next or have an idea on what the problem might be.
Wanted to ask here before I format and reinstall as a last option.

[Frank Wallis]

Are you using your personal wireless Router which is connected to ISP Modem?

You don't have to bring in extra router or play with the encryption settings?

Please don't play with the IP address configuration,if it is set to assigned IP address dynamically,let it be that way.

Just right click on your Wireless Network Connection icon in your taskbar on your desktop and click on "View Available Wireless Networks" and see if you are able to view the network in your Wireless Network list?

What do you see in your Wireless Network List?

[matsm]

No I don't have a personal router.
We have played a lot with the encryption, trying WPA2 and WEP and completely disabling it.
We have tried both static and dynamic IP address config.
I can see the network when I open the networks list, when I try and connect to it it tells me Windows could not connect to the network. I also see a few other networks, but they are all encrypted too.

Further more the landlord has one more network running for the house nextdoors, we tried to connect to that one too but without success.

We are both puzzled by this, my landlord used to work in IT for over 10 years and myself I'm a second year IT student.

[Frank Wallis]

So what messege do you see when you try to click on that network?

[matsm]

Windows was unable to connect to network.

Bought a new network adapter today and with it we managed to connect to a secondary network, but it has not internet on it. We still need to figure out the fault with the primary network. The new adapter would not connect to the primary network

[matsm]

Got a USB adapter that is the same make as the modem and router it now works, still dodgy but works.
Seems there was a few things over at the modem and router end that was not configured and installed properly that caused additional problem, what they are landlord wont tell me but he told me there were some.