Some Fools come saying that under Aurangzeb so and so Hindu General was working. Can U forget that Aurangzeb only came to power with military and not by peaceful means. He knew that he could not harm the powerful Hindu generals since who had been serving since Akbar's times (i.e Ancestors). But, once he got control of the Army - and with the death of some of these generals then he set upon killing the sons of these generals.
Moreover, don't forget that these were traitors. Can U forget Pritvi Raj Chauhan - Mohammed Ghori only managed to defeat him because of PRITVI's traitor Father in law. i.e. There were more Hindu traitors aligning with these invading Muslims rulers thinking that these invaders would return to their own kingdoms.
And can U Forget the great Sikh History - read it and U will understand how 90% Kashmiri Hindus became Muslims.