Mp Symmetry Issues

Hi Folks, I have an old Toshiba L350-159 laptop that I haven't used for some time and though I'll check it out to see if it still works OK. However when I turn it on tries to boot Windows 10 but never seems to get past the loading window timer before the computer reboots. I've run a full RAM test (2.5Gig) and all tests are fine. I've even formatting the hard drive and, tried another hard drive but again the laptop still reboots at the same point. I contacted a friend who let me try his Geek Squad (v5.7.1) diagnostic software which runs perfectly and every test passes until the diagnostic software get to testing Core 1 of the processor with shows a MP Symmetry "N/A" but Core 2 seems to pass all the software tests. If I get the software to just run the MP Symmetry tests, Core 1 does not show any tests being performed but Core 2 does.
Do I have a problem with one of the processor dual cores not working correctly?

Any advice would be appreciated.
Regards
Geoff.