What should I do to prevent crashing?

Extremely recently, I acquired a new laptop for use in a variety of things. One of these was to download Unity and resume coding as a hobby. However, I have had a nasty amount of lag and crashing that has not ceased to worsen. Now, the computer I have should be able to run this. It is an Intel Core i7-2670QM, with 8 GB of RAM and a 64-bit Operating System. Furthermore, when I got it, it was reset to standard conditions, so I don't have any junk running in the background or even just taking up space in the memory.

Nonetheless, almost every time I try to Run my code in 3D settings, it will work for all of 2 seconds and then crash. Initially, this didn't happen, and I was coding happily for a couple hours, but the problem has just worsened. I have tried uninstalling and reinstalling Unity and restarting the laptop, but nothing has helped. So now I appeal to the Unity community for something that will obviously seem trivial to you, but which I am utterly confused about.

Thank you!