This service allows you to convert Roman characters to Arabic characters by yping Arabic words phonetically in English script and still have them appear correctly in Arabic. This will become helpful if you are using a computer that does not support Arabic characters. You can then copy and paste the Arabic characters in programs such as MS Word. Please visit Google ta3reeb for more information.
Click HERE for a tutorial on how to enable Arabic in Windows XP. When Windows 8 is available (by the end of 2012, I will create tutorials for it.