If you are using Eclipse IDE you can simply hit restart button in console it will automatically restart

What the heck ?

Just click start then type in search line at the bottom "services"

and run it or go to the control panel and click twice on administrative tools icon

you should see a list shortcuts, there will be "Services" shortcut, run it.

Find service named "openerp or odoo" and just click restart or stop/start

For Linux installation, you can use the following command in the terminal:

sudo service openerp-server restart

The above line assumes you have included "openerp-server" is the name of the service as you have configured in /etc/init.d

for ubuntu this will may help you:

--> First got to your addons folder in your system

--> ./openerp-server --addons-path=GIVE YOUR ADDONS PATH

-->if you want to restart server on different port then you can use "--xmlrpc-port=8900"