This morning I turned on my computer but instead of booting up as usual it made a lot of whirring noises, switched off, then turned itself on made a lot of whirring noises then switched off, repeating this for what would have been an indefinite period if I hadn't switched off the power. It only started correctly when I disconnected the power cable. Now I am afraid to turn off the computer at the end of the day for fear that I won't be able to get it to start up again. This would be a disaster as I am in the middle of arranging my mother's funeral. Can anyone help?