WiFi disappears after 10.7.5 update on iMac

I am having the same problem. This is so frustrating. I do not have an Ethernet cord to connect to the router with, so I have to use my iPod to look for a solution. I thought about downgrading by reinstalling lion, but would that affect my files in any way? I don't want to have to do a clear reinstall. Anyone have this issue and find a solution yet?

Same issue here. It is no good for meeting clients on café. How can we roll back to 10.7.4?

Actually, i manage to make the WI-FI reappear after the 10.7.5 upgrade. I did reset the SMC as advise on other thread and it did work. I hope that can be a solution for you too.

I found this solution on the internet and it worked perfectly for my Macbook Pro.

If you do get the “WiFi: no hardware installed" error after upgrading to MacOSX 10.7.5 (you can use the reinstalling ‘patch’ of the old IO80211Family.kext system extension. Instructions for doing so can be found here:

http://macmanusnl.wordpress.com/2012/05/17/1074_refuses_to_see_atheros_ar9280/

By the way, I believe this upgrade does not allow you to downgrade the system; the smart move is to fix the WIFI driver.

Good Luck, I hope this works for you too.

Norgard, I am having the issue with 10.7.5. I installed it last night and haven't been able to connect via wifi since. I am either going to reinstall Lion if I cannot find any solutions. I'm going to try the solutions other people have just suggested soon. I suppose another option that may fix it would be to upgrade to Mountain Lion.

I just tried Zipt's solution and it worked. All I had to do was download the two files, drag the plugin into the utility app that is downloaded and let it repair the various files. After a restart, my wifi hardware reappeared.

Hey there. I had the same issue as soon as I updated to 10.7.5 (Lion) on Friday morning. After spending countless hours troubleshooting my router and my MacBook Air, talking to Apple Care, visiting the Genius at the store and searching the forums/net for an answer, I got the issue fixed. I also use a Netgear router and there are a couple of issues with the update, one being that it doesn't work with the old Netgear firmware. Here's a complete step-by-step on how to get it resolved. My internet is working flawless now for a few hours and faster than before.

1. Update Netgear Firmware: If you can't of course do this from your laptop, try another device (phone, iPad, tablet, etc...).

Enable the Wi-Fi, connect to the router, and go to:

http://192.168.1.1 Type in username: admin password: password

Should automatically tell you there is a new software update. If not, go to Router Upgrade.

2. Go to Wireless Settings (in Netgear): --> CHANGE CHANNEL to 3 or 9. --> CHANCE SECURITY to WPA2-PSK [AES]

3. Let it refresh. (Wi-Fi goes offline and then back on).

4. Go to Network Preferences on the MacBook (or laptop device) ---> Advanced --> and delete your router from the preferred list.

5. Go to Macintosh HD (hard drive) --> LIBRARY --> PREFERENCES --> SYSTEM CONFIGURATION --> and under developer, DELETE the following three (3) files:

com.apple.airport.preferences.plist

com.apple.network.identification.plist

NetworkInterfaces.plist

6. RESTART the computer.

7. Go to Network Preferences: At the top, click on LOCATIONS and add a new one. Call it whatever you want. Then make sure when you are done, that it is now working off the NEW location.

8. At the left, you see the pane that has the Wi-Fi or Bluetooth or whatever device listed. Click on the gear at the bottom --> SET SERVICE ORDER. Again, make sure the Location is the new one you just created. Choose Wi-Fi.

9. Connect to your router: Make sure you are using the NEW location.

10. RESTART computer.

Check and make sure you are connected. If you aren't connected, let me know.

Just an FYI:

If you call Apple Care (whether you are in warranty or not) let the first POC (verification department) know you are calling about a software update issue. They will transfer you to tech support. Once they transfer you, tell the tech specialist you want to be transferred to the Wi-Fi specialists. Yes, they actually have a team of Wi-Fi specialists!!

Most of the steps I got from reading the Apple forums here. The only thing I didn't see anywhere was to change the channel to 9. She said it might get busy so remember the channel setting process and change to 3 or vice versa.

Don't listen to any of these that say download this patch or revert to 10.7.4, etc... Just keep 10.7.5 and do these things.

Hope it helps! Let me know 😀

If you guys delete the network from the Preferred Network List and rejoin the network after a reboot, does that resolve the issue ?

Have you tried creating a new location for the wireless network and trying ? Also try rebooting your router once and check if the issue persists.

These are some things that have helped folks in the past.

It doesn't work that way. If you read my post (above yours) it explains the issue in the first paragraph. It's a combination of deleting 3 specific files, rebooting the router, updating the firmware on the Netgear router, creating a new location, manually entering a new location, changing a channel on the router, and restarting the computer a few times in between. Mine is still working fine!!!

Same issue here. Every other device connected to Apple Base Station except my MBP, which just updated to 10.7.5. It said "no networks found" when trying to log into my hidden newtwork. After an hour I stumbled into a solution. System Prefs>Network>Assist Me (bottom center of window) Next window select Diagnostics. The red lights under "Network Status" one by one turn green. Selecy "Continue" Choose WiFi. Pick your Network and enter password. (In my case I had to choose "use closed network" Enter network name, choose WPA Personal, enter password) Now a dialog appears "Network Change Detected" Click continue. Now (this from memory) it asks to "Select a Location" I Choose Automatic. Connection restored.

I hope this works for some of you like it did me...

Just be careful...if you use a Netgear router, it could eventually keep failing on you because the actual firmware on the router needs to be updated to work well with the 10.7.5.

Are you sure it was not just the encryption change that fixed it. Did you try those changes before upgrading the firmware?