HT4628: Wi-Fi: How to troubleshoot Wi-Fi connectivityLearn about Wi-Fi: How to troubleshoot Wi-Fi connectivity
Currently Being ModeratedJan 21, 2013 11:27 AM (in response to HKTMCC)
Try using an app like iStumbler to check for interference. Also try changing your WiFi channel on your router.
Currently Being ModeratedJan 21, 2013 1:19 PM (in response to HKTMCC)
Thanks will certainly try this. Location of the imac has not changed though, only difference is the OS
Currently Being ModeratedJan 22, 2013 4:03 PM (in response to HKTMCC)
Even if upgrading the operating system is the only change you made, there might have been coincident changes to the environment. For example, one of your neighbors might have changed his wifi settings to conflict or bought a defective new microwave or similar device.
Currently Being ModeratedFeb 7, 2013 10:47 AM (in response to HKTMCC)
Had the same problem (random WiFi disconnects), but AppleCare solved it.
Delete Macintosh HD/Library/Preferences/SystemConfiguration.
You'll have to reconnect WiFi, but pswd etc should still be there.