The sequence goes like this: When logged on, I click on "restart", the program shuts down, there is a black screen, then there is this message: "1962 No operating system found. Press F1 to repeat sequence". (I didn't write it correctly in first post.) Pressing F1 only repeats the error message. Ctrl-Alt-Delete launches correct start-up, so the error message apparently appears before grub loading.
There are apps that claim to repair the problem but it's not clear to me what the problem is and the 'fix' is for MSWin O.S. This machine did have XP on it which I replaced with Linux Ubuntu and Kubuntu. Grub boot is on sda1. After booting up, there are no problems.
Does this clarify things?
Originally Posted by marco18
Sorry but when does this message appear?? Before grub loading? Maybe it has to do with a corrupted MBR or an incorrectly configured active partition.