Have you ever visited Betawatcher.com?  

This site is where you can download free MMORPGs for free, all are free to play as well. They also give up to date info on upcoming ones too (both free and payable ones).

I have played several which gave me no problems and a whole lot of fun, all being free: 9 dragons, Tantra Online, Last Chaos.

Check it out and let me know what you think of it.

I am thinking of playing Aion or Cabal next.