I had a friend who had that happen, years ago. It confused the heck out of technical support, as there was no documentation on how to handle a valid Windows suddenly going invalid. Obviously the tech could not help my friend to reinstall Windows. It got escalated twice, and finally a supervisor sent a new hard drive fully loaded with all the original software sold with the computer. If you are within your year's warranty, you could try that. Just keep persisting, and ask for supervisors, and let them come up with their own answer. I wonder if you'd get a push-back if you SUGGESTED a new fully loaded hard drive, as they may not make fully loaded replacement hard drives any more, like they used to. Just persist for resolution, if you're under warranty. Once a problem is identified, you'll usually keep on getting help, even if the resolution takes longer than the existing warranty period to resolve. I would push on the "invalid" part harder than on the slow startup issue. It is possible that pushing on either issue would also solve the other, but pushing hard on one issue will more easily get a sympathetic tech response than pushing on the other.
