For help licensing and downloading EnRoute, check out this article first: Activating your License and Downloading EnRoute
Once you've downloaded the .zip file, extract the contents to a known location.
Inside, there will be 4 more zip folders. You will only need one of them:
The vast majority of users will use the 64-bit Installer. EnRoute_X_Installer_32bit.zip: Use this if your operating system is 32-bit. The majority of systems are 64-bit these days so you won't be using this one.
Rather than extract the zip folder, you can double click it to open it like a folder and then double click to open the .exe.
The Installation Wizard will then appear. Click Next, and then "I Agree".
Choose your destination folder. The default location is C:\EnRoute7 and should be adequate unless you have set aside another location or hard drive for it.
Click Install.
The Software will now install. Please wait for it to complete.
During the installation, the installer will prompt you for your measurements units. Click "yes" for Millimeters and "No" for Inches. This can be changed inside the software later if you decide otherwise.
Enter the activation code you received in your email OR located on your account at saicloud.com.
The installation will then complete.
You have the option of putting a shortcut on your desktop. Click Finish to finish the installation