Intel iMac Not Connecting to My Airport Express

Question

I have had a 15" G4 Powerbook for about 1 1/2 years now and have not had any problems with my Airport Express. I purchased an Intel iMac back in February and everything has been working perfectly until about two weeks ago. (I think this may coincide with the update 10.4.9).
At first, the Airport would not connect at all after being put into sleep, either if I let it sit or pushed the button myself. I would have to restart to get it to work. Now, whenever I attempt to connect to my Airport Express it says there is an error and only gives the options of trying again or just clicking OK. If I try again it does nothing, but if I click okay the Airport card in my iMac seems to go down completely and I am unable to see ANY wireless networks at all! It comes back eventually and automatically connects to an unsecure network somewhere else in my apartment building, but if I try to connect back to my Airport Express the same thing happens again.
The odd part is that my Powerbook connects flawlessly, and also sets up the Airport Express if I reset it (something the iMac will not do). I have read through some of the threads and see there is an issue with the release of 10.4.9, but my Powerbook has it as well and doesn't have any issues.
I also have Vista premium installed and that has absolutely no problems connecting to the network either, which is irksome every time I see a PC vs Mac ad.
I have tried a couple of the remedies offered up: deleting the SystemPreferences folder in the Library (couldn't find it), creating a new location (didn't work), and reinstalling OSX (worked for a day after the 10.4.9 update).
If there is anyone with similar problems who has found a solution, please let me know, as I don't really like using someone elses network, but don't really have a choice if I need to use my iMac. Thank you for your help.
iMac 17" 2Ghz   Mac OS X (10.4.9)  

Answer 1

Hello sgraziano,
I suggest taking a look at this article named iOS: Troubleshooting Wi-Fi networks and connections found here http://support.apple.com/kb/ts1398.
Follow these steps to troubleshoot the above issues.
Be sure that you are in range of your Wi-Fi router (access point).
Tap Settings > Wi-Fi and turn Wi-Fi off and then on again.If unable to do so, see this article.
Confirm that your Wi-Fi router and Cable or DSL modem are connected to power, turned on, and indicate that they are connected to the Internet.If not, refer to your network administrator or ISP for assistance.
Restart your iOS device.
Tap Settings > Wi-Fi and locate the Wi-Fi network to which you are connected. Then tap > and Forget this Network. Try to connect to your desired Wi-Fi network again.
Note: You will need to enter your Wi-Fi password again if your desired network requires one.
Turn your Wi-Fi router off and then on again2. If your ISP also provides cable or phone service, check with them before attempting this step to avoid interruption of service.
Update your device to the latest version of software.
Update your Wi-Fi router to the latest firmware2.For AirPort Base Stations, see this article for information about firmware updates.
And this section at the bottom if that troubleshooting does not resolve hte issue:
Unable to connect to a Wi-Fi network
Verify that you are attempting to connect your desired Wi-Fi network.
Make sure you are entering your Wi-Fi password correctly.Passwords may be case sensitive and may contain numbers or special characters.
Reset network settings by tapping Settings > General > Reset > Reset Network Settings.
Note: This will reset all network settings including: previously connected Wi-Fi networks and passwords, recently used Bluetooth accessories, VPN and APN settings.
Take care,
Sterling