How old is the laptop?
Does it get very warm or even hot prior to the "freezes"?
When you first turn on the laptop, go to the "Type here to search" box and enter "Reliability History" (or "View Reliabilty Histor").
Set for Days. Then start looking and clicking the red circle icons and yellow triangle icons.
Select and use right click to see the technical details. Look for error codes - especially any that occur just before or at the time of the freezes.
The information is going to be confusing - even if not BBC....
First focus on just being able to navigate around. Then the next effort will be to look more at the errors and idenfity some specific problem.