How to enable Arabic typing in windows vista?

To add the Arabic language support in English version of Windows you need to follow these instructions:

1. Click on "Start" button and then select "Control Panel".
2. Under "Clock, Language, and Region" area select "Change keyboards or other input methods" link. Note: If you are in the Control Panel "Classic View" then double-click on "Regional and Language Options" icon and click on the tab "keyboard and languages".
3. Click on the "Change keyboards…" button then click on "Add…" button.
4. Expand "Arabic (your Country)" tree then Expand "Keyboard" tree from the list.
5. Make a check mark beside the required keyboard(s).
   Note: You can preview any keyboard before adding it by highlighting its name then click on "Preview…" button.
6. Click "OK" to add the selected keyboards to the "Installed Services".
7. Click "OK" to confirm and apply your new language settings.

Note: If you add more than one keyboard to the same language; you will notice a keyboard icon in the language bar which enables you to switch between the language keyboards.