Greeting Non-Muslims

The word 'Salaam' is a quality of Allah meaning 'Peace'.

It is not permissible to greet non-Muslims with "Assalaamu'alaikum".

If a non-Muslim greets a Muslim with the Salaam, the Muslim should reply with:

"Wassalaamu alaa man al-tabaa`al-Hudaa."
(May peace be upon the guided ones)