OpenERP 7 does not requires a web client and a desktop client. In fact there is a client and it is web client. When you install openerp, you must use your browser to access your instalation. On a typicall instalation, you must point your browser to localhost:8069

Since there will be no databased on the system you will be forwarded to the Manage Databases windows, where you will be abble to create your first database, choose the language, decide to use or not demo data and must provide 2 passwords. The first is the default one "admin" that allows you to manage databases on the system, and a second, called database password, that will be the password for the administrator user for the company you are creating.

After the creation process, you will be redirected to a page called Apps where you will be abble to install your first module. All modules are installed from this Apps menu. This is accessible in Settings / Apps, or Settings / Installed Modules (for local installed modules)

It will be helpfull to be abble to see all functionalities for the administrator user, and you must activate a specific setting for the administrator. On settings menu for the database you have created, point to Users and click on users. You will see an Administrator user. Click on it, and click on edit button on top. Next to Preferences tab, there is a Access Rights tab, where you define the overall access rights for the user. Scrool down and check an option that says "Technical Features".

Save and reload the page with F5.

Welcome to OpenERP

Paulo