Moved desktop to new location in home, can't connect to internet

Question

Quick bit of background- I was using a _PowerMac G4_ downstairs in my house with a _2Wire (wireless modem)_ connection. Upstairs, I had a PC also on the 2Wire. Both connected to the net just fine.
A couple of days ago, the PC died, so I moved the PowerMac upstairs to where the PC was. Now, I am unable to pick up the internet using the 2Wire attachement. The message that I get is: +"Safari could not log in because you are not connected to the internet."+
The other thing that I noticed is that I do not have the AIRPORT icon in the top right of my monitor. Instead of the three or four curved lines, one beneath the next, I am seeing an icon that looks like a telephone receiver. The impression that I get is that either AIRPORT is turned off or that the computer doesn't recognize that it has it installed.
I've tried all of the normal HELP routes:
+- Restarting the modem+
+- Going to Apple icon -> System Preferences -> Network -> (when I get this far, AIRPORT is not listed in the left-hand column as an option, nor is it listed in the drop down for CONFIGURATION).+
+- I click on ASSISTANT but, although AIRPORT is listed, I can't select it as one of the options.+
I tried SBC Yahoo U-verse tech support but they don't have a lot of training with Apple products so I didn't get very far with them.
I recall, when I first placed the G4 in its original location, I had a similar problem. I was able to resolve it through U-verse tech support after a bit of time. I wish that I could remember the details, but I think that it had something to do with the version of OS X that I had not recognizing AIRPORT and having to perform some sort of cheat. (For the heck of it, I tried U-verse support a couple of times hoping that maybe the next tech that I got might know about this issue, but no luck so far).
Does anyone have any ideas or suggestions?
*PowerMac G4*
*OS X 10.5.8*
*Wireless Connection through 2Wire Gateway 3800 HGV-B modem*

Answer 1

Three tips that may help out in your situation:
• Your Airport card might have a loose connection; open your tower and make sure the card's properly connected; if the airport card itself is malfunctioning, replace it with a new one; otherwise, you won't be able to add a preferred network name in Apple pulldown/System Preferences/Network.
• Consider getting a better modem/router (e.g., 7550 ADSL2+Gateway); from what I understand, the 2-WIRE routers are based on older, less reliable technology.
• Make sure the security protocol's set to WEP; that's the only protocol that the Airport card in a PowerMac G4 can understand. If you try to set the security protocol to WPA, the handshaking between WPA and the Airport card will fail and your computer won't be able to join new networks. In short, WPA's not backwards-compatible with PowerMac G4s; it's only compatible with the newer Intel-based Macs, which, by the way, are more flexible than PowerMac G4s in that they can communicate with a broader range of security protocols, including WEP and WPA.
Good luck.
applegala530