If you have set your Mac to allow apps only from the App Store and you try to install an app from elsewhere, your Mac will say that the app can't be opened because it was not downloaded from the App Store. If your Mac is set to allow apps from the App Store and identified developers, and you try to install an app that isn’t signed by an.
Tip
Hey,
A new feature in Mountain Lion is the ability to protect your Mac from running applications that are not from authorised developers. This means developers from the App Store and identified developers apps will run normally. Those apps that are from other sources will automatically be disabled, and not run. This is a security measure to ensure no malicious code runs on your Mac. However, if you like downloading and running apps that are not from the usual source, you may want to turn this off. This post will show you how.
Allow Alternate Applications To Run
To allow any application, downloaded from any source to run you need to change a system preference setting. Open up system preferences in your applications folder. Select the Security & Privacy preference. Under the general tab there is an option to select which applications run depending on there download source.
This little system preferences option will allow you to change settings.
You can then pick the option you want. If you want to be very safe you can pick Mac App Store only. If you want to run your computer normally I would select the second option of Mac App Store and identified developers, I don’t see why it has to be any more strict than this. If you want an app downloaded from anywhere to run you select the option entitled anywhere.
Its a simple setting, however if you experiment with applications downloaded from various sorted, you may want to select the third option.
