Arabic language pack-windows vista ultimate

I bought and Installed Windows Vista Ultimate that is in English language. System is running fine, no problem. But due to some reason I want to install the Arabic Language on this system.

Can anyone please tell me where can I get the same? Many thanks.

You can get it through Windows Update. Just search/run the updates and install. if you want you can directly download from the below URL as well:

Vista Arabic language pack