MY COMPUTER SHUTS DOWN AND THEN STARTS BACK UP WHAT CAUSES THIS?

I've experienced this myself a few times. In the shutdown selection you typically have several options - to put the system on standby, shut the system down or to restart the computer. Sometimes when I've been in a hurry, I've accidentally clicked on "restart" instead of shut the system down. And when you hit restarts, it does shut the system down and it comes back up again. Hopefully, this is all it is with you. Doublecheck yourself before you actually shut the sysem down. Make sure you are selecting "shut system down" instead of "restart". Good luck.

Your computer is automatically installing updates so it has to restart so updates are installed.

You should shut down and install updates since it is easier as it wont disturb to your next computer meeting.

You most likely have a virus... When it is rebooting, press "F8" and choose to disable reboot.....................etc.

Then when it boots up again, it will not reboot. You may get a blue screen with a fatal exception error. Try to reboot again, press "F8" and choose safe mode with networking. If you can get in, run a virus scan.

there are some programs that have bugs and that is one cause of this problem. i had experienced this problem and the problem seems to be Nero inCD4 (do you see a blue screen?) if you have the same problem try uninstalling inCD4(if you have it)

Probably a bug or virus that you have. just restore your computer

virussssssssssss