My keyboard stopped working after Mountain Lion install

Do these resets to clear errant commands:

SMC RESET

http://support.apple.com/kb/HT3964

• Shut down the computer.
• Unplug the computer's power cord and ALL peripherals.
• Wait 15 seconds.
• Attach the computers power cable.
• Wait another 5 seconds and press the power button to turn on the computer.

The 5 second timing is important to a successful reset.

PRAM RESET

Zap the PRAM

• Shut down the computer.
• Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.
• Turn on the computer.
• Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.
• Hold the keys down until the computer restarts and you hear the startup sound for the second time.
• Release the keys.

I have excatly the same problem on Mac Pro 3.1.

I too have the same problem. I have an early 2008 MP and I cannot get anything to work (even Apple's own USB keyboard). I hope they fix this soon.

same here. MacPro3,1, Apple USB keyboard and mouse work fine when I boot from the 10.6.8 HD, but when I boot from the Mountain Lion drive (installed that yesterday) - no keyboard, no mouse.

(well, I did have some "success" with the old old round mouse that came with the original iMac back in the days, but it's very erratic to say the least, and one of the very early USB keyboards, but most keys go into 6x repeat mode when you press them).

can't believe it's Apple, makes me almost feel like I've just installed one the early Windows incarnations...

further to this:

it's getting weirder by the minute. this morning I grabbed my original iMac mouse & keyboard to see if using these I could at least set up the Bluetooth ones to work, restarted ML - only to find out that now my latest USB mouse & keyboard do work!

so I started testing various software, rebooted at least several times - all good. but somewhere along the way, I got the infamous "No Wi-Fi hardware installed", even though Wi-Fi works fine on my Mac under 10.6.8. so I did some reading, and decided to do the SMC reset. did that, restarted, and guess what? my USB mouse & keyboard ain't working any more !!??

If you have AirPort card - remove it. I did, and USB is working fine 😉

Someone else suggested exactly the same thing in another thread - verrry strange, but I guess I'll give it a shot nevertheless, thx.

done that - and indeed it did the trick. thx.

My iMac does the same thing with mountain lion. It started last week but now does it all the time. Withina couple minutes of turning my computer on the mouse only shows a right click and the keyboard does not work. My iMac is also a 2008. I tried the troubleshooting steps here both SMC and PRAM did not work. I reinstalled mountain lion and I still have this issue. It's at the point I can't even use my computer anymore. In fact I am having to type this on my iPhone. Any help or suggestions would be great! Thanks!

I just fixed this problem -- before doing crazy restarts, resets or taking the computer in, try this:

Go to Applications > Utilities > Audio MIDI Setup

On the left side, you'll see a list of inputs and outputs -- mine says "Built-in Microphone...Built-in Input...Built-in Output...LogMeInSoundDriver

Right click on "Built-in Output" > drop down to "Use this device for sound output" ... and boom goes the dynamite, my sound is working again!

I realize now that since I have been using a remote desktop to access my imac for the last 6 weeks, the remote desktop grabbed the sound on my imac, so when I got back to working on my imac, the audio settings were configured for my remote desktop, not my imac.