No network signal

So you're saying you're connected to the wireless netwok, but not to the internet?
And it works for windows?

What program are you using in linux to connect, and what wireless security mode are you using on the router (had some troubles in the past myself)?

Also, does it work if you just plug the network (by cable) in your ubuntu machine?
Further, if it's secure wireless, can you set the router just for a try to unsecure and try to connect (just for diagnostics, not as a permanent solution)?

I am connected, but no interent. Yes Windows works fine. I am using Network Manager on Linux to connect. The security on the router is set to wep with a wep key. I will try later on this evening when I am home to try and connect with no security. There is a cordless phone next to the Ubuntu machine. I am gonna remove that this evening to and she what happens. Just trying to eliminate everything.

WEP in the gnome network manager applet (?) should be fine. Sometimes Linux shows you that you're connected even though the security doesn't work - but in this case I'd guess it should be ok. You could still play around with the security settings though.

An additional thing you could try, if it's a http interface router, whether you can access the configuration menu of your router from linux.

Last night I was unable to acess the router settings via firefox. I tired connecting with no security, which didn't help. I removed the cordless phone that was next to the pc and that didn't help. I tried different things with the security, nothing seemed to help. I couldn't even get connected this morning. It would show the network, but no connection. The connection status said it was connection to wifi wlan0, showed no ip no nothing, said the driver was b43. Was wondering if the driver could be the problem? I installed the ndiswrapper appliciation and was using the driver on the Linksys disk I thought. I don't believe that is the b43 driver. Now, the command sudo is messed up. It says can't resolve host. This has happened a few times already. I believe it's something I am doing to cause it. What though, I have no clue. When this happens I just format and reinstall cause I don't know what to do. I am new to Linux. I think I caused the sudo problem this morning. I was looking in network settings and the host for the Linux pc was listed with a loopback ip address. I know that wasn't right. I deleted it trying to add the host back with something other than a loopback ip address. I think this is what messed the sudo command up or I could be wrong.

I looked around in the board, found some other people who had the same sudo problem. I tried there suggestion and it worked. I learned what I did wrong to cause the problem and now I know who to fix. Now, if I could just get this network problem solved. So far I love Ubuntu, but I am not liking the never ending network problem.

Sorry, I think I really don't have much of a clue now.
I think I never had a network problem in recent days in linux (else than wireless issues). To eliminate or confirm that it's a wireless problem (rather than a network settings problem), you could try to connect by cable (either plug the network port into the router, if you have, or take the network cable that runs from the modem to the router and plug it into your computer).
alternatively, you can connect "by hand", by editing your /etc/network/interfaces (bake sure to backup it before playing) and then use ifup wlan0 and ifdown wlan0 accodingly. You can find more info on the web on it. here's an example of a "manual" interfaces file:

thias@neuron:/etc/network$ more interfaces.pi.1
auto lo
iface lo inet loopback
address 127.0.0.1
netmask 255.0.0.0

iface eth0 inet dhcp

iface wlan0 inet dhcp
wireless-essid [the name of the network]
wireless-key [your wireles key in hexadecimal, I think, but maybe ascii works too]

Not for sure what this had to do with it. All I did was blacklist all the b43 drivers leaving the Windows driver. Rebooted, that didn't work. So I uninstalled the Windows driver and the Windows Wireless Driver App. Rebooted, leaving nothing install. I then unblacklisted all the b43 drivers. Rebooted, that didn't work. So with the b43 drivers still unblackisted, I then reinstalled the Windows Wireless Driver App and the Windows driver. Rebooted and it worked. Has been working all weekend along. Thanks for all your help. Problem is now solved.