Trouble is, the update will not install. It will attempt to do so several times, before I get the message that there is a "reverting" to the computer's previous status. I haven't the option of not letting this happen repeatedly, since every time I turn off the computer the same nightmare begins. Then, it's very difficult to get things going again the next time I turn on the computer. The update is said to be "critical" to security, so I'd like to have it on the machine, but....