Save the file to your desktop and double-click it to begin the installation, selecting options you desire when presented.
Part 2: Once installed, activate the software with key & ID. There should be a Malwarebytes icon on the desktop, double-click it to open the program. If there is no icon, you can go to the following folder:
C:\Program Files\Malwarebytes Anti-Malware<<<<this folder(for 64bit versions-C:\Program Files (x86)\Malwarebytes Anti-Malware)... and double click the mbam icon in that folder
Once open, click any 'Activate' button and you will get a new dialog box labeled 'Activate Product'. Insert the ID in the first section and the key into the next.
Please make sure you are COPYING and PASTING the license key & ID numbers directly from the confirmation email into the proper fields. Please also make sure you are only including the letters and numbers and not the words ID or Key. Finally, make sure you are not including additional spaces before or after the ID and Key.