The first thing to do is to check the system requirements for the antivirus because it's possible you don't meet those requirements in order to install the CD. By default, McAfee Antivirus requires the following to install successfully:
-Windows Vista SP1 (32-bit and 64-bit)
-Windows 7 (32-bit and 64-bit)
-Windows 8 (32-bit and 64-bit)
-Windows 8.1 (32-bit and 64-bit)
-1GB RAM for Vista and Windows 7
-2 GB RAM for Windows 8 and above
-500 MB free drive space
-1 GHz processor
Typically, you should have the possibility of installing it on every computer. To do this, insert the CD, then open My Computer/Computer. Right click the CD/DVD-ROM drive and choose Explore. Locate the executable file that starts the installation (usually named as SETUP.EXE) and right click it. Choose Run As Administrator and then wait for the wizard to start. Continue by setting the installation options and that's it. The application will install normally.
Notice, that the antivirus will run only on Windows machines. To download the Mac version of the antivirus, visit the following website: http://www.mcafee.com/us/products/virusscan-for-mac.aspx
You will need a new registration code as well since the serial can't be applied to a version that's working for another operating system.