Probably I will have no other choice, but to format the HD, and install clean a new OS. This is a personal computer. It is a little bit an old computer. Bios is probably from 2007. May be if I install the HD in a new mother-board it may start. I do not know if it virus. Probably there was a power outage (sudden loss of electrical power) and somehow one segment of the HD got damage. There is probably a way to put it up and running,and recover it. But probably it can not be done with free software. I would be willing to buy. But it is risky. there is not a clear diagnosis. If I buy a bootable antivirus, and it is no a virus. Or what about if I buy something to fix a partition problem, and it is a virus. It is guesswork. And money is in short supply. The HD I think is large (a little bit bigger than one tb), but it used to work well with this mother-board. Why it is not working now? I always back-up important information. This is for me a little technical challenge. Should I abandon the idea of recovering this HD? I have just tried [another] recovery disk (free) to no avail. It does not work. As simple as that. There is no way to contact them (at least without registration). What do you say (if I may know)? Learning all this is time consuming. But I am interested in PC repair, to see if I can make an extra busk, and have fun. Have a nice day!