Enterprise Architect is distributed as a single executable setup file EASetupfull.exe, since Version 12 EAsetupfull.msi. After you execute this file, Enterprise Architect is immediately available to create projects as .EAP files. All MDG extensions are stand-alone installation routines, the download information is described in the license email.
Corporate, Unified and Ultimate edition users planning to use SQL Server, MySQL, PostgreSQL, Sybase Adaptive Server Anywhere, Access 2007 or Oracle 9i, 10g or 11g as their model repository can access scripts that create the required data structures for the choice of DBMS.

The latest test version and the registered full version (with previous versions eg. 14 is always  the latest build offered)  Enterprise Architect are always available on the Sparx Systems website. The full versions are on the registered user area of ​​the site provided. A valid user name and password are for access necessary. These data are obtained by the purchase of the license (s) and are from date of purchase for valid for 12 months.
You can check here the running time.

The system requirements for installing Enterprise Architect are defined on the Enterprise Architect | System Requirements page.
Windows Vista
Under Windows Vista (with User Account Control turned on) an application starts with only Standard permissions, regardless of what level of authority the current user has. As a result, an installer run normally with an Admin account under Vista only has Standard privileges and either is not able to write to certain critical areas of the registry/file system, or redirects the write requests to a per-user virtualized registry/file system.
Sparx Systems recommend that if you are installing on Windows Vista, always run the Enterprise Architect installer with Administrator privileges (right-click on the downloaded installer icon and select the Run as administrator menu option).

Installation on Mac or Linux
The instructions for use on non-Windows environments are summarized here  WINE is recomended.
How to install Enterprise Architect
Enterprise Architect is distributed as a single executable setup file EAsetupfull.exe). In general, you can accept all the default options without changing. To install Enterprise Architect in a different directory, enter the destination path. You may be asked at the end of the installation process, restart the computer. Please follow this call.
After you execute this file, Enterprise Architect is immediately available to create projects as .EAP files.
If you plan to use the Corporate, Business and Software Engineering, Systems Engineering or Ultimate edition with SQL Server, MySQL, PostgreSQL, Access 2007, Sybase Adaptive Server Anywhere or Oracle 9i, 10g or 11g as a model repository,you  can use scripts to generate the necessary data structure for their chosen DBMS. These scripts are on the following pages described. You may require additional files and supplementary installation processes.
Please note that installation and maintenance of these database management systems is not covered under the support agreement.