Currently Being ModeratedAug 16, 2012 5:28 AM (in response to themattman27)
This method will delete the partly downloaded copy of the Mountain Lion installer. If you had already installed Mountain Lion, it won't delete the installed operating system.
Currently Being ModeratedAug 16, 2012 5:34 AM (in response to David Empson)
OK i have done it. I am new to the mac, so you don't have to have those icons on launch pad in order to have it? or is it because it's a OS, and if it's on your system then you don't need it?
Currently Being ModeratedAug 16, 2012 6:04 AM (in response to themattman27)
The Mountain Lion you saw in LaunchPad was a partially downloaded copy of "Install OS X Mountain Lion.app". It is just an application, which happens to install an operating system. LaunchPad shows applications on your computer (including partly downloaded ones). LaunchPad does not show the installed operating system as a whole, nor does it show non-application components of the installed operating system.
If the application is a self-contained installer (typically for an operating system, but there are also application installers for other software components, such as Adobe Flash), then when you run the installer application and go through its questions, it installs the software contained within the installer onto the computer. Once you have done that, the installer application is no longer needed (unless you want to install the same software again later). Deleting the installer application has no effect on the software which was already installed using that application.
In this case, "Install OS X Mountain Lion.app" installs the Mountain Lion operating system, and if you go through its questions, it would normally upgrade or reinstall the operating system on your startup drive, restart the computer when done, and the installer would be automatically deleted. It then would not appear in LaunchPad any more, because there is no longer an "Install OS X Mountain Lion.app" on your computer.
You would be running Mountain Lion at that point, but the running operating system does not appear as an item in LaunchPad.
Should you happen to download another copy of "Install OS X Mountain Lion.app", that will end up as an application on your computer which you can use to install another copy of Mountain Lion (or reinstall Mountain Lion on your current startup drive). That downloaded copy of the installer would appear in LaunchPad, but again if you deleted it, it would have no effect on the running operating system - you are only deleting the application which installs Mountain Lion. You are not deleting the operating system.
Currently Being ModeratedMay 23, 2013 2:46 AM (in response to David Empson)thank you for one of the few good clear explanations re: a component of mac os that i have found. i too am new to mac and was confounded that the app store offered to download mtn lion to a used mac mini that i had already upgraded to mtn lion. i would have thought the app store would've known it was already installed and would've made me go thru a few more hoops before allowing a possible re-install. i think your explanation also helps me to get the gumption to delete one of the TWO copies of iMovie (both both say "iMovie'11 when i check drop-down "about iMovie") that are on my application screen after i downloaded '11 as an updrade to the pre-existing iMovie'09. now, if i can just figure out how to get photos in "photo library" off iphone....... (yes, "camera roll uploads no problem to 'iphoto' and 'image capture' but the "library" album photos on iphone iOS6 won't). haven't found any lucid explanation of this roadblock, only descriptions of uploading 'camera roll' - which is not the problem.kyle