gergy, thanks. I have one more choice now No need to be in a hurry to buy/install SU at all. As time goes by, SU will be more mature, as well as other choices. I tried SU a couple of days. It seemed fine. However, I tried some software installation in ShadowMode yesterday, and I found some traces of the installation left after reboot. It means that my disk was not protected as expected. I still have not figured out what is the problem yet.