My Pc don't can to see hard disk (sata) I would like to know why. Luis

Have you had problems with your computer being slow? if this is the case, chances are you have a big virus and the computer can no longer read your hard drive. This will also make it much more difficult to to reinstall the OS. I would suggest taking it to a local computer store, not a box store, and get them to reinstall the OS. It sounds like you may have a boot virus. If this is the case, it also means you will not be able to retrieve any information you had on your hard disk prior to this incident. Let me know if this is the issue. If not, we'll try to figure out something else.