Windows XP with Office 2003 and the addition of the Proofing Tools will probably
satisfy all needs for writing in Arabic. (Spellchecking, thesaurus, dic tionary,
etc.)
We obtained Arabic keyboards years ago for our old Windows 98 machines - they
still work just fine on the XP machines. go to Google or eBay for various
suppliers.
They are easier to use than the on-screen keyboard built-in.
Otmar Foelsche