Hi bullionboy,
Is it a Desktop or a Laptop?
Does the computer shut down only while using the Video editor?
Check the status in BIOS. Restart the computer and tap F2 on Dell logo and check if the computer shuts down.
If its a Laptop, I recommend running diagnostics (restart the computer by holding FN and Power button simultaneously) on the computer to test the hardware.
Awaiting your response!
