If you would like to have a second In-house EP installation which you are going to use for testing purposes ONLY, then you can make a copy of your existing one and set up a 'clone' on a base of it on the same server. Please be aware that there is no way to easily rollback any global changes made on a production EP account, thus the ONLY meaning of having a second one is a firsthand acquaintance with In-house installation benefits and ability to perform tests of the functionality.
In order to 'clone' your EP account you need to do the following.
1) Back up your existing EasyProjects database using the SQL Server Management Studio.
Locate your Easy Projects database, right-click on it and select Tasks - Back Up.
2) Restore a database from the backup under a different name (e.g. "EasyProjects-test") on the same SQL server using the SQL Server Management Studio.
Click on Databases and select Restore Database.
3) Create an empty folder (e.g. "EasyProjects-test") at 'c:\inetpub\wwwroot\' where EP files of the second instance will be located.
4) Create a separate application pool (e.g. "EP-test") in IIS Manager, choose .NET 4.0 and "Integrated" mode for it.
5) Create a new Web site/application (e.g. "EasyProjects-test") in IIS Manager and choose just created application pool to run with it.
6) Make sure you have downloaded the EP installer of the same version as your original EP In-house installation from:
1) Run the EP installer in the 'Upgrade' mode.
2) Browse to choose the path to the folder where EP installation files will be created (e.g. c:\inetpub\wwwroot\EasyProjects-test) at the corresponding step of installation process.
3) Enter 'sa' user login credentials and choose the name of the restored database (e.g. EasyProjects-test).
4) Choose the virtual folder/application (e.g. EasyProjects-test) created earlier in IIS.
Finish the installation.