What a joke. Mountain Lion cripples my iMac.

You have a problem with that particular system that needs to be fixed. See Understanding upgrade nightmares.

Uninstalling is a challenge.

It would be a lot better to find out what's causing the problem in the first place.

A lot of the problems people are having around stability have to do with 3rd party extensions that are incompatible with Mountain Lion. Try entering this from the Terminal and pasting the results here:

kextstat -kl | awk ' !/apple/ { print $6 } '

I sympathise, but you are an "early adopter" as we say, which is a complimentary way of saying "sucker". Every version of OSX has been a big mess at the beginning, early adopters work out the bugs and by 10.x.3 it is pretty good. If you don't have the patience for beta testing software, wait 6 months next time.

There are applications I can't run. For example, Google Chrome Helper runs my processor at 100% and it overheats the computer which runs like a turtle. I had to disable that application, and it is fine.

You can open Activity Viewer in the Utilities folder to see what is slowing you down so bad. There is a column for processor percentage that's useful for diagnostics. There is a quit process button once the bad process is selected. Some processes, however, relaunch immediately. Those nasty things require special intervention.

Failed to follow sane and safe upgrading practices and don't have either a bootable backup/clone or Time Machine backup of your previous Lion installation?

Tsk, tsk.

See these for more details:

http://www.macmaps.com/upgradefaq.html

http://www.macmaps.com/backup.html

http://www.thexlab.com/faqs/installswupdates.html

http://www.thexlab.com/faqs/backuprecovery.html

Air Display has some cases where it will kernel panic a Mac:

http://blog.avatron.com/post/28135386805/kernel-panics-mountain-lion-and-bluetoo th

You may wish to try uninstalling it and seeing whether it helps.

Are you sure you're up to the latest version of VMware Fusion? Only versions priori to VMware Fusion 4 used kernel extensions, to my knowledge. Try uninstalling VMware Fusion entirely for a bit and re-running that command and seeing whether the VMware extensions are gone, and whether your system starts behaving better.

Glad we were able to help. The root of the problem is that computers are complex beasts, and while Apple can test with thousands of third party products, they can't necessarily test with all of them in pre-release testing.

Kernel extensions plug in at low levels of the OS and while Apple will disable ones they _know_ cause problems, they don't necessarily have the time to test or the ability to test with them all (you have to figure, there are literally tens of millions of software configurations on end user systems). So a little troubleshooting can go a long way.

Hopefully the 3rd party software vendors can update their software in short order, so all end users have a better experience!