Computer restarts on its own;then won't reboot fully.

[ingeborgdot]

I was downloading an update to a program I had had for some time now. The update did not get all the way through when it caused my computer to hiccup and then reboot, only it didn't reboot fully. I finally got it to reboot and I quickly uninstalled the program along with the update hoping that was the problem but when I came down to the computer this morning it had restarted and didn't finish the reboot. Does anyone care to venture into this problem?