Yes i have 3 HDD attached. if I use them with my another computer they work without any problem.
Sorry, just not understanding your post.
Your first post said the problem began when you first installed Win 7. Did you run Memtest or any other diagnostic program to troubleshoot hardware at that time?
Your next post said you didn't have a problem when you removed the HD's... With no HD's how did you boot the machine to test?
Your next post said that they worked fine in another machine, how would you know that without reloading the OS for that hardware?
Your last post said you were thinking 'bout replacing the MB, why would you do that without knowing it is your problem?
Sorry, just a little confused!