Hey Terry - Seeing how the machine will still boot into Safe Mode this is almost certainly software related, most likely a driver.

Go through the list of installed programs and see what new software has been most recently installed. See if your neighbor can identify one of the most recent installations with the beginning of the BSOD issue.

Also, go into Device Manager and check if there are any yellow (error) icons associated with any of the devices. Let us know if any devices are showing the error icon.

See this guide for help with troubleshooting the BSOD: https://davescomputertips.com/2011/11/troubleshoot-the-dreaded-bsod/

Cheers...Jim

So, the machine is rebooting every 30 seconds even when in Safe Mode??

Hmm, well Terry seeing how the system will not remain loaded, even in Safe Mode, I'd say that is indicative of a hardware issue. Because the system is actually loading, I don't believe it would be anything too serious such as hard drive failure or faulty motherboard. My guess would be an overheating problem, or maybe faulty RAM. Check that all fans are spinning okay. If all fans are operating properly - remove any RAM cards, clean the contacts with white spirit (metho will do) and then connect the RAM card(s) again.

You could also try disconnecting all peripheral devices plus any other hardware which is not needed for the OS to load - optical drive(s), excess RAM, graphic card and any other PCI cards.

If none of that proves effective, the best way for your neighbor to proceed would probably be to take his PC to an authorized repairer where they have the necessary equipment (meters, etc) to properly test the various hardware components.

Sorry can't be more help,

Cheers...Jim