Need Help To Install Mcafee

This is happening as if you go to system preferences > general the option of App Store and identified developers is checked .

And it is recommended do not install any third party anti - virus , unidentified apps in your Mac .

And if you open safari & its preferences > file download location is set to ask for each download and this a security set , so that if you try to download an unidentified app it will prompt to enter admin name & password and without entering both fields , the app won't get download and open safe files after downloading must be also unchecked .

As installing mcafee in your Mac computer will bring more issues , there is no need to search the methods of how to install it .

Particularly for Mac computers NO ANTI - VIRUS must be installed ,

And Mac gatekeeper is stopping it download .

Read this article : OS X: About Gatekeeper - Apple Support

Some apps downloaded and installed from the Internet could adversely affect your Mac. Gatekeeper helps protect your Mac from such apps.

Gatekeeper is a new feature in Mountain Lion and OS X Lion v10.7.5 that builds on OS X's existing malware checks to help protect your Mac from malware and misbehaving apps downloaded from the Internet.

The safest and most reliable place to download and install apps is via the Mac App Store. Apple reviews each app before it's accepted by the store, and if there's ever a problem with an app, Apple can quickly remove it from the store.

For apps that are downloaded from places other than the Mac App Store, developers can get a unique Developer ID from Apple and use it to digitally sign their apps. The Developer ID allows Gatekeeper to block apps created by malware developers and verify that apps haven't been tampered with since they were signed. If an app was developed by an unknown developer—one with no Developer ID—or tampered with, Gatekeeper can block the app from being installed.

MacAfee and other 'credible' Windows Anti-Virus products have been cited on these forms as causing far more issues then they claim are out there for Mac. The fact it's failing to register itself may be a blessing.

Return it and get your money back.

That's something you would need to ask the McAfee folks.

When you start to experience problems on your machine, the very first thing you should do in troubleshooting is remove this.