Sony Vaio laptop always crashes cause?

Hello here have an old Sony Vaio laptop MODEL: PCG-7186M and always crashes every 5 to 10min. Get a black picture and have to strangle it. I also wanted to rebuild Windows, but I'm not getting that far.

There are many causes most of the time the CPU fan is full of dust, which can be carefully sucked from the outside (vacuum cleaner) set weak.

Also, the hard drive could have many sectoral errors with the years.

You should not put in a lot of time money.

Defective battery?

Thanks, let's see