I have been on the phone with APPLE CARE this morning and they were very helpful and enabled me to fix my wifi issues.
Before speaking with APPLE CARE I tried so many of the unusual little tricks on this board (and others) which seemed to be working uniquely for certain people. It turns out the problem in my case isn't LION as such, or my WiFi rather it's to do with the SECURITY on my ROUTER.
I had an old MacBook at home which was very useful as I was easily able to make the adjusments on my Router through this to then later allow my new iMac (LION) to log on etc.
I'm using a NETGEAR router, but the procedure will be much the same for other routers etc.
What I did was sign in to my router (on my older MacBook in my case):
http://192.168.0.1
Put it my USERNAME and PASSWORD (which, by the way, is usually:
USERNAME: admin
PASSWORD: password
Then selected WIRELESS SETTINGS.
Within WIRELESS SETTINGS there is a subheading entitled WIRELESS SECURITY.
Within WIRELESS SECURITY there are four options:
1) Disable
2) WEP (Wired Equivalent Privacy)
3) WPA-PSK (Wi-Fi Protected Access Pre-Shared Key)
4) WPA-802.1x
I had
2) WEP (Wired Equivalent Privacy)
!! THIS WAS THE PROBLEM !!
According to APPLE:
WEP is being used less frequently as it appears to be not as SECURE as it's contemporaries (namely WPA etc). As a result LION struggles to communicate with the router using this security. BUT the good news is it CAN be easily changed!
For a home setup Option 3:
3) WPA-PSK (Wi-Fi Protected Access Pre-Shared Key)
Seems to be the best option. Option 4 is a for a bigger setup (I wasn't listening too much, but apparently it's more suited to businesses using their own servers/networks etc?!).
Next things we did was:
SELECT OPTION 3:
3) WPA-PSK (Wi-Fi Protected Access Pre-Shared Key)
After selecting it asked me to enter a new password, so I did.
Then I selected APPLY (or SAVE depending on your router). It took a minute to load...
Then I went on to my new iMac (LION) clicked on
SYSTEM PREF > NETWORK > ADVANCED and REMOVED (pressing the negative / '-' symbol) the network I've been struggling to get on for the last two days.
Then ADDED (pressing the positive / '+' symbol) a 'new' network giving it the same title obviously as the one I had just deleted. It'll ask what SECURITY you want of the options, but just leave it as 'None' (as your WiFi will work it out itself). After this press ADD, then OK in the next window. Lastly press 'APPLY'.
After this - go up to your WiFi putton on your top bar, click it, then select the new network you've just created (which will of course have the same name as your old one) then when asked for a password put in your NEW ONE as you created on your ROUTER...
...Alas IT SHOULD WORK!
It did for me, and the chap on the phone was so very useful and said this will be in the info they'll be putting on the discussion boards ASAP. I'm sorry if ym explanation has been a ittle convoluted as I'm not a techy person, but wanted to share this after sharing the struggle with so many.
Good luck!
