I would suspect the graphic card driver, or that the screen resolution is set too high.
Safe mode boots the pc with the minimum, but working MS drivers.
You could try safe mode, then device manager, and uninstall the graphic card driver. Then do a normal boot .
Windows should fall back to a reliable MS driver running in SVGA mode, or just above that. It should be stable.
I would also run 'sfc /scannow', to try to correct any simple Windows O/S problems.
Best source for the drivers would be Toshiba's site.
( Of course it could also be overheating but not if it's fine in safe mode.)

 

After completing the installation it seems to be working fine now, although on one reboot it carried out a disc check and found lots of errors, I ran seatools suspecting a hard drive issue but it passed all tests. So at the moment it seems to be working fine.

 

Both your original problem, and the reported drive errors suggest a power problem to me (instability). Running ok in safe mode = not using power-hungry video settings.

?? Win 7 ?? How old is this laptop and battery?. Check this for ideas and tests https://www.techspot.com/community/topics/my-laptop-keeps-turning-itself-off.197492/

 

Hi, I am having the exact same problem now zz
I have cleaned out the CPU/Heatsink etc and I have re-installed Windows 7 did you find a solution?