Q: Update Mountain Lion 10.8.5 Macbook Aluminium 2008 can't used Wifi (can't on wifi)

I have the same problem with my late 2008 and 10.8.5. The suggested fix does not work for me - just for the next reboot:

Anyway, if I turn off WIFI (just deactivate) before I shut down or restart my macbook and activate it again after restart - it works.

The 10.8.5 supplemental update did not solve the problem.

Have the very same problem.  It started when I installed the 10.8.5 update suggested by Apple. To test what the problem was, I reinstalled version 10.8 and immediately the problem was corrected.  Then Apple suggested the upgrade again to 10.8.5, which I installed. As soon as the upgrade finished and I re-started my computer, the wifi was gone again.  I downloaded version  10.8.5 COMBO from Apple, as suggested and this corrected the problem. I also noticed that there are three types of 10.8.5 upgrades offered on the Apple site, and obviously the one that Apple suggested for my computer (2009 MacBook Pro) was not the correct one. My gratitude to the person who suggested downloading this update.

MacBook Pro, late 2008 (5,1)

OS X 10.8.5

This is clearly a software issue, not hardware as some have suggested. I didn't want to do a 10.8 reinstall - actually would be a problem because our IT would have to do it. And I trust them not. PRAM reset did not work.

So I tried the delete WIFI in System preferences solution, then created a new WIFI connection and it works!  I've rebooted, put the laptop to sleep several times and it has continued to work without a hitch.

The issue presents as this; when you click on the wifi icon in the menu bar to start wifi, nothing happens. Usually it does not even show the broadcast bars, but if you reclick on the icon it says it is searching, but not finding, any networks. And this continues without end.

To repeat the solution:

Go to System Preferences under the Apple icon menu (upper left of screen),

open System Preferences then click "Network"

if your System Preferences are locked (icon in lower left corner), unlock them

click on Wi-Fi in the window listing networks on the left side so it is highlighted

click on the minus ( - ) sign below the window

delete the Wi-Fi connection

click the Apply button at the lower right corner of the System Preferences window

Close System Preferences and restart your computer

When back at your desktop, return to System Preferences

click on Network

click the plus sign ( + ) under the window where you just deleted Wi-Fi

It should ask if you want to create a new Wi-Fi connection, do so

Turn on Wi-Fi as you normally would using the icon in the menu bar

select the network you want to join and re-enter the password, etc.

You should be good to go.

I updated my late 2008 macbook to OS X 1.9 (Maverick) today.

The problem is solved now

Same exact issue, thank you for the solution!  I've re-booted a number of times since trying this and it's worked each time.    Now hopefully Apple will solve the issue.  I can't update to Maverick yet because I work for a company that doesn't know if a program I use to access my work will be compatible with the update...grrrr.....

This made my problems even worse! Now I can't even add a new network!!! Thanks for nothing mate, sorry...

I have done this too many times in past 2 months  and it's worked ok but still is blocking and needs a restart or two or four this morning over here in France ....

don't give up on it .... do the steps .... if not working first round, disconnect power, restart and do process again ....

this morning after 2 tries, I did not apply and did another restart and it seemed to matter, it then caught ok ...

and don't forget the **** cable box itself ... you may want to restart that during a particularly tough "get it going" since too many things get "locked in" ....

boring ....  this is not our fault, it's APPLE asleep at the switch !!!

don't put it on Davizzlle .... put it on Apple ....

and be patient ... it's ugly and boring but it's still our problem to live thru, be patient and and and .....  I get your frustration .... I've got kids and work at home and cannot lose 10 minutes just with wiFI apple screw up -- but have had to 50 times in past months .... 

share the pain TOWARDS  APPLE ....

we are all just sharing !!

best

Upgrade to Mavericks

or

if you need to shutdown the computer (and your Wi-Fi is working) turn Wi-Fi off before shutdown. Then, when you power on, turn Wi-Fi on and it will work.

Well... I hoped that upgrading to Mavericks would solve the wi-fi problem on my computer... instead it loses connectivity every 5-10 seconds and then reconnects. Not too happy with this.

Mavericks also solved my problems, but I'm sorry to hear that it's increasing the pain for some others. If your connection drops every 5-10 seconds, maybe that's repeatable enough to take to Apple Tech Support.

Have same problem. Mavericks didn't fix. It's very annoying - i have to delete wifi every time i start my macbook and then restart and rediscover wifi to get a connection...