On my desktop computer, I have had Windows 8 installed for a few weeks, but decided to return to Win 7. So with Win 8 there is a place that says something about doing a either Refresh your computer and keep your files, and there is one to do a total re-install of the system. Well I did the "Total Re-install like it came from the factory". I'm paraphrasing of course but it's something like that. Anyway It did it's job. There is nothing left on the computer which is fine, but when I try to install Win 7, Win 8, and even Win Vista, I just get a message "An operating System wasn't found. Try disconnecting any drives that don't contain an operating system". I sure hope somebody can help me.