I've tried almost everything and this simple thing finally works for me (tested for more than 1 day):
Solution: move from WEP to WPA2-Personal authentication
- Make sure you have WPA2 setup on your wireless router
- Forget the previous wifi connection on your iMac; you need to delete it
- Access and add your Wifi router again; verify by going to "System Preferences" > "network" > "Wi-Fi" > "Advanced" > "Preferred Networks" that under the security tab it shows WPA2 Personal.
My 21.5" mid-2011 iMac used to work fine with WEP under Snow Leopard and then Lion but started giving connectivity problems after moving to Mountain Lion. Usually disconnecting and re-connecting to Wifi worked.. sometimes restarting router.. but it was super embarrasing to me (as a fanboi) whenever my wife accessed my machine and there wasn't any network.
BTW, I'm running 10.8.2 and also updated the supplemental update 1.0
Hope it helps you as well.
I still love my iMac and Apple!
I've done everything. I've had a case open with Apple phone support for a month, spent a week at the local Apple Store having them look at it, reinstalled the operating system (10.8.2) and this thing still won't wake from sleep.
This is my first Mac and before I upgraded the op system to the latest, was a good machine (2011 Mac Book Pro 13"). I've had it! I wanted to get my wife to try and make the switch over to this machine from our old Windows laptop, and she refuses. I don't blame her.
I think Apple is getting too fat and full of themselves, just like RIM did !
Yet another Mountain Lion bug.
OSX is becoming windows. When I was on SL everything was solid, since "upgrading" to Mountain Lion I spend almost every day for nearly a month now fighting my computer. The computer is supposed to work quietly in the background, that's why we buy mac, that's why we paid extra.
This OS is junk.
I too have bitby the latest upgrade. I think between the iOS6 on iPhone 4 issues and this ML upgrade on my mid-2010 mac, I am no longer an Apple fan. I actually think my Windows 7 PC is less problematic. I hate to say it, but it may be time to part ways. Woudn't hurt quite so much if they didn't have $100 Billion dollars in the bank to address these issues. I wonder if Apple even reads these posts at all. All of the issues I have are ALL over the internet.
The simple WPA fix worked for me too. After installing Mountain Virus, I had constant drops in wireless connection which only seemed to get worse with OS updates. I tried every fix on this support community, including reinstall of OS with no joy. I was at my wits end until a friend noticed that my router used WEP password and suggested I tried WPA instead.
2 days later - so far so good.
Mountain Goat. Love it . Are Apple interested?
Glad I held off installing IOS 6 on my mobile devices and will wait a long time before I upgrade my iMac OS ever again.
When you get an OS upgrade on a Mac you expect to enjoy a plethora of great new features - not suffer a host of annoying problems.
Get it together Apple. No more releasing half cocked operating systems!
Have Apple jumped the shark?
Agree with "jumping the shark" analysis, I've shorted the stock. Their decline will take time but it starts w core users bailing.
They need to enter a period of stability, be happy with what they have done, lock it down, make it rock solid. Desperate attempts to "add features" just breaks what WAS working and ****** off customers. We don't need iCloud, Facebook integration or any silliness. Just make WIFI and AUDIO work dammit! [ha face palm]
WIFI is huge. They should have had a support page regarding WEP and WPA.
Everyone has different needs, but in my mind, the following is huge for me:
1. Smoother WIFI (was a problem, but now fixed for me)
2. Support for Preview and access to Preview iCloud on the iPad.
3. Less program crashes/freeze (occurs several times a week).
4. Better searching for Email (I usually get on gmail to search).
5. Faster wake up time from sleep.
6. Better and more prompt support if there is a problem, such as problematic WIFI connections, based on number of complaints.
1. The sequence of the links on the bookmark bar does not sync with my Ipad.
2. Smoother syncing for Pages and Numbers.
3. Email option to make a default email address when composing.
4. Default option for recovering webpage tabs from last browsing session.
5. A little more functionality regarding automatic text replacement.
Just adding to the pile of people who're having WiFi issues with Mountain Lion. I have a late 2008 MacBook Pro 15". Intermittent WiFi connectivity, sometimes with download speeds as low as 0.5 Mbps (or no connectivity at all, despite excellent signial reception)...essentially the same problem that everyone is having.
Here's what I've tried so far, all have failed:
- Cleared all router/Airport entries in Keychain, "forgot" all Prefered Networks, created new Location, renewed DHCP
- Changed MTU to 1453
- Router was already set to WPA/WPA2
- Updated firmware on router
Anyone have any new homegrown solutions?
I'm at the point where I've stretched an Ethernet cable across my living room just to submit this post. Obviously, no one at Apple will read my post, but my hope is that I can at least add to the crowd of affected people to help draw Apple's attention to this problem. At the very least, they could be professional about it and acknowledge that there is a problem, regardless of how it's being solved (or not being solved). I would gladly give Apple all of their Mountain Lion swiping, sharing, and alerting in exchange for functioning WiFi.
Same as everyone else...
I have a late 2008 MacBook Pro 15 inch on 10.8.2 that can't connect to the Internet.....seriously THE most ridiculous bug I have heard of.. It's 2012, almost 2013 Apple, and you can't update an operating system without effecting a feature like connecting to the internet? Every other piece of electronics in my house does a better job of connecting to the Internet than my $2500 mbpro. Work it out!! F ing ridiculous!! I have every Apple device on the planet, apple stock, and I'm still considering jumping ship. FIX IT!!!
I know right?
When my wifi suddenly went useless I Googled it and of course it was another known bug, which of course they have done nothing about. How could they break wifi?!?! Just leave everything alone Apple, SL was working great!
It's amazing how quickly they were able to forget everything Jobs knew. Wisdom can't be transferred down to new generations. Jobs dies and suddenly we are back in 1999 with bugged out PC like machines! You just gotta laugh.