Yesterday, Feb 16, I downloaded and installed Microsoft's latest security updates. This morning, when booting my computer, I received a message saying that my computer could not verify that my operating system was validated in my name. I tried to boot again, received the same message. Finally, I re-started my computer and everything was fine except for Checkdisk, which took only a minute. Could this be a coincidence, or has the update altered something so that I may eventually have to reinstall XP?
Something similar here also. My PC would not boot in any mode the morning after (must have been out on the town!) so had to "restore" using Acronis to get it going. Then downloaded and installed again the updates, since when the PC has been OK.