Issue with the High Sierra OS System for my Apple PC

Hi There,

When my Dad upgraded our PC to High Sierra, the systems keep crashing.

It just automatically turned off and won't turn on. Sometime it stuck with the white screen.

When he restarted the PC, the system loading up about 50% then it will automatically restarted again and it will keep going in this loop and could not open the login & password screen.

He then redo the OS and put it back into the factory mode but this issue still occurred, the screen just automatically turned out at any time and white screen still appear and with the same problem in open the login & password screen.

Could you please advise how to fix the problem or where can I download the update? Please see below part of the log on the date the system crashed. Please advise on how I fix this problem?

“Mar 10 09:58:31 localhost syslogd[40]: Configuration Notice:

ASL Module "com.apple.networking.networkextension" sharing output destination "/Library/Logs/CrashReporter" with ASL Module "com.apple.networking.boringssl".

Output parameters from ASL Module "com.apple.networking.boringssl" override any specified in ASL Module "com.apple.networking.networkextension".”

Thank you.

Teresa