Select the Windows start button and select Settings.
Choose Time and Language
Select Region and Language
Select Add a language then choose Arabic
Choose the Arabic (Saudi Arabia) language and install. When installation has finished you will return to the Region and Language page.
Select the Arabic (Saudi Arabia) language and choose Options
Under Download Language pack, select Download then under Speech select Download
When downloads are completed under Speech the download button will be replaced with a Settings link
To confirm that Microsoft Naayf has been successfully installed, under Speech select Settings then under Text-To-Speech, Microsoft Naayf should be in the list of voices.
That is it, you can now select the Microsoft Naayf for use in Read&Write