Hello Howard. Sorry to hear about the inconvenience caused. I would request you to follow the steps in the article to below to sort out your issue.
http://windows7themes.net/en-us/missing-operating-system-windows-7/
Hope this helps. Please feel free to contact us should you need any further assistance.
This morning I was prompted to run an update for AVG Antivirus Free. I run two machines, and the prompt appeared on both machines. On the first (running Windows 8.1) the update and re-start worked fine (AVG version 2015.0.5941 now running). On the second (running Windows 7) the update ran, but after re-start I got the message "Missing Operaing System" on a black screen! Just a coincidence, or a problem with the update? Anyone else had this problem?
Hello Howard. Sorry to hear about the inconvenience caused. I would request you to follow the steps in the article to below to sort out your issue.
http://windows7themes.net/en-us/missing-operating-system-windows-7/
Hope this helps. Please feel free to contact us should you need any further assistance.