My ACER (all-in-one computer) stop working, when I boot, it has a black screen and one line message onthe top says 'Operating system not found', since I created a set of recovery disks right after I bought the ACER, I try to use them, but they did not work (get to the point to choose either to recover the system and data or just the system without data, it stops, won't go further). not sure if my HDD is still good, don't know how to check that. At this point, any help will be appreciated..