As for a virus or spyware, I definitely had one... it changed the wallpaper to a red WARNING and any process you wanted to do, it would show the warning. This is the one -- http://www.fasterpccleanclean.com/remove-warning-your-re-in-danger-wallpaper. I seem to have gotten rid of it, although I am not sure all registries and dll's have been deleted. I bought Spyware Doctor and am unsure what all it did.

As for the HD failure warning, in a previous thread, I wondered if it could have anything to do with the power supply overheating, as mine sometimes was getting super hot. My dog destroyed my Toshiba power supply by chewing it and I bought a third party one. Which functions but who knows, maybe it is not same quality as the original. I still wonder about that power supply.