Wireless Connection Unavailable Message /Adapter

I need technical help. I feel like I need to tell the whole story to help my chances.

Four years ago, I bought a used computer with an updated windows XP. I wanted to use the internet so I bought the linksys router (WRT150N) and adapter (WUSB300N). I used their cds and got them connected. I don't remember how exactly I got it, but I got it. A few months later, my brother bought a computer from the same place that he never used. Two years later, my computer crashed. Two days ago, my brother gave me his, that he never used. I connected it up and I went to use the internet.

Trouble started to come when I could not find the adapter CD. I searched online and eventually found an updated version of the software to my adapter. I downloaded it, transfered it from my one computer to another, and installed it. It worked.

The problem came with connecting. I couldn't connect with any of the routers/networks that I found. So I went to the main computer and changed the name of my router/network. Then, I found my name come up several times with different MAC numbers, but none of them worked. I eventually put in the exact code, IP address, Subnet Mask, Default Gateway, DNS1 and DNS2. However nothing worked.

What I mean by work is, it would connect (the linksys). A couple times the connection had 300m(something) and downloaded bites. The problem was the Network Connection kept saying Wireless Connection Unavailable. I do remember when I got my original one to work four years ago, two of those things at the bottom (taskbar) came up and one would say I connected and the other one said I wouldn't. I tried to set up another connection, but I couldn't.

As for the router hardware itself, it looks like it is working. It looks normal. Both bulbs come on and the one that always blinks, blinks.

I don't know what to do and I am lost for words. Can anyone help me? Is there anything I need to download? Anything special I need to do? Thanks for any help.

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