Hi,
Above all it will take some time to fix such a rebooting issue with discussing on forum. Based on the situation I suggest to contact Microsoft online support instead.
Back to the case. First you can test to boot into Safe Mode to see if it will still keep rebooting.
If you can boot into Safe Mode, it could be a driver related issue. Try to uninstall all drivers in Device Manager including sound card, display card and network card, reboot to see if you can boot into Normal Mode.
***You will not able to access internet after uninstalling network card so make sure you have its driver before uninstalling.
*the screen resolution will be small (desktop will be large) after booting into normal mode. This is normal as the display card driver is uninstalled. Reinstall could get it back to normal.
In addition, if there is no much important data, perform a system repair or even reinstall system will be a quicker workaround. To do this you need an installation disk if you have a product key for your system, or a recovery partition (generally it will occur
on a laptop with system build-in).
A reboot issue could be caused by different factors. Sometimes we need to collect mini dump
files for analysis.