Help....can't configure AEBS

Question

Have tried repeatedly to set up AEBS to connect both my iMac G5 and iMac G4 wirelessly to internet via my DSL modem and ethernet connection. Both have built in Airport Extreme cards.....both show in System Profiler....and have established computer-to-computer connection, so both cards are working.
I have reset the AEBS and have also disconnected everything for days in frustration and in hopes it would return to factory default setting.
Steps I have taken so far:
1) I connected power to AEBS.......light is steady;
2) Turned off and disconnected ethernet cable from my iMac and connected it to the WAN port on AEBS; turned modem back on...both port lights on either side of AEBS power light blink for a few seconds then go out;
3) Opened Airport Setup Asst.; selected Set up new AEBS...none found. Selected Change settings on existing network (I had diddled with this last week and thought I'd configured an AEBS network). It found the name of the network I tried to create earlier (I can't get rid of this and start over); I continued...was asked for keychain permission; said yes; meanwhile..."joining network..." is still searching....as is 'color wheel'......no AEBS found; scan again.....same thing....."error occured connecting..." because there's nothing to select and connect to. It's not finding the AEBS.
4) Opened Airport Admin Util...try Rescan...nothing; try Other....get 10.0.1.1; asks for password.....doesn't seem to care what Iput in...scans....with color wheel; then "unable to read config of selected (Other) base station".
5) Network settings are:Automatic, Show-Airport (shows the network I set up before); Airport selected; configure IPv4 automatically; using DHCP, apply now. Tried setting it to PPPoE but it won't allow and resets to DHCP.
I have repeated these steps; read the manual that came with it; read the Discussions that I could find; reset; rebooted; even, via Pacifist, reinstalled Airport Setup Asst. and Airport Admin Util. No change.......but old network name still reappears as soon as AEBS is reconnected...despite App reinstall and default AEBS settings!!.
Don't know why, but I believe the AEBS is working. Even after turning off Airport on iMac, the AEBS port lights occasionally blink as if searching. Iknow the AE cards are working....but I'm doing something wrong. Can someone please help me? Thanks.
iMac G5, 20 (Rev. A); 1.8 GHz; 233 GB; 2 GB Crucial   Mac OS X (10.4.7)   Virtual PC for Mac & Windows XP Prof. in iMac; also have iBook G4, 10.4.7; AEBS

Answer 1

Well some progress has been made. I have Airport Setup Assistant configured; and Admin Utility......I think. It recognizes the base station but I still can't connect to the Internet. The status report in Network Diagnostics says everything is 'green' except: Internet failed and Server failed. I've shut down and pulled the plug on the modem and shut down the computer for a few minutes, then reconnected power to the modem and restarted it, then booted the computer, hoping it was the modem.
I got info on IP, Subnet Mask and Gateway addresses from my ISP but that's all he knows about Macs. I was on the phone with the AppleCare Tech for an hour and a half trying everything right from scratch but still nothing. He said I didn't need those addresses. We had a power outage while talking to him. He called me back but I couldn't continue until the power came back. I've been working for two hours since then and everything seems to be a 'go' except the connection.
I'll check tomorrow with my ISP to see if I need a DHCP Client ID, but
could it be a setting in Network or Sharing Preferences? Or in the Admin Utility Config selections I've made? There are so many choices within Airport...Internet...Network...WDS!!!
Any further suggestions would be welcomed. Thanks.