Cheapest solution: Open it up, take out the GPU, reflow it, repaste it, put it back in. Does require a little know how.
Expensive solution: Buy a new GPU. Absolutely not worth it.
Expensivest solution: Buy a new machine. If you don't dare do the cheapest solution, this is likely the most logical option.
Your files are not gone btw, you can easily take out the harddrive and use it with another machine.