After crashing...

what to check for error? The laptop just went dead and turned off. I was watching video in VLC player, and it turned off. After turning it on again, what do I need to check to see what was the cause?

Hello Dick Jagger,
Start by checking the temp of the machine, is it overheating ?.

Next check your file system.
Open a command prompt as administrator and type sfc/scannow press enter and let it scan, if errors are found you will need to scan again until clean.

Download and run these free apps.

CCleaner - Optimization and Cleaning - Free Download (Backup Registry When Prompted),

Malwarebytes

Check in the Event Viewer for any clues.

Give this a try, good luck and post your results.