Wifi doesn't stay connected with 2010 MacBook Pro after upgrade to Mountain Lion After upgrading from Snow Leopard to Mountain Lion the Wi-Fi on my 2010 MBP basically stopped working. It would stay connected for a few minutes at a time and then drop the connection, connect, drop, etc.

My Wi-Fi access point continued to work with all other devices - it just stopped working on this one machine.

It appears that this issue is also in Lion - there are many threads on discussions.apple.com with users complaining about similar issues:

https://discussions.apple.com/thread/4144707?start=0&amp;tstart=0

https://discussions.apple.com/thread/3191630?start=0&amp;tstart=0

https://discussions.apple.com/thread/3235078?start=0&amp;tstart=0
The only solution I found that actually worked was to replace the Mountain Lion Wi-Fi drivers with the ones included in Snow Leopard.

NOTE: This solution is not for the faint of heart and please ensure you've backed up your system - at worst this should only bork your Wi-Fi (which I'm assuming is already broken if you're trying these steps) but it's better to be safe than sorry.

Insert the Snow Leopard DVD into your DVD drive.

Open a Terminal:

sudo -s
cd /System/Library/Extensions
mv IO80211Family.kext /Users/&lt;your acct&gt;/Desktop 
cp -R /Volumes/Mac\ OS\ X\ Install\ DVD/System/Library/Extensions/IO80211Family.kext .


Run Disk Utility and Repair Disk Permission on your system drive

Rebuild the kext cache:

sudo touch /System/Library/Extensions


Wait a few minutes to ensure that the cache has been regenerated and then reboot.