There are number of issues that can cause your laptop to freeze.
How long is it on before this happens ? Could be cause of overheating. Dust built up in the chassis and vents or
on top of something causing it to to not get proper ventilation.
Installed software running, Anti-Virus, etc..
Right Click Windows Start Button select Event Viewer, Windows Logs > Application
Look for critical errors that say app hang, app crash, or anything that relates to the CURRENT problem.
Note the event ID, and the source codes and Google search them or post here.
Could be corrupt system files try this first Right click Windows Start Button select Command Prompt (admin) type or copy paste sfc /scannow
It could be a hard drive that is going bad or corrupted. Virus on PC, run Full System scan.
To check a hard drive use chkdsk Right click Windows Start Button select Command Prompt (admin) type or copy paste
chkdsk c: /f /r
Not enough RAM could be another cause