is it possible to buy a graphics card and install it into a hp laptop?

Solution
Short answer: Yes, but it is not worth it

Little bit longer aswer: Your cpu is not powerful enough, but if you want to buy the gpu and the dock (your laptop won't be mobile anymore, might as well get a desktop.

Here is an awesome overview from life-hacker:http://lifehacker.com/5851902/turn-a-low-powered-laptop-into-a-gaming-machine-with-an-external-video-card-dock
Yes, but they are expensive and require a lot of extra pieces, not to mention external power. Some are usb 3.0, some use PCI expansion slots, some use thunderbolt, and there are a few more obscure ones.

This link has a few of those reviewed, but for some of these prices, you're probably better off buying a $1000 Lenovo laptop with an 860m graphics card.

http://www.notebookcheck.net/Review-External-Graphics-Cards-for-Laptops.112162.0.html
 
Short answer: Yes, but it is not worth it

Little bit longer aswer: Your cpu is not powerful enough, but if you want to buy the gpu and the dock (your laptop won't be mobile anymore, might as well get a desktop.

Here is an awesome overview from life-hacker:http://lifehacker.com/5851902/turn-a-low-powered-laptop-into-a-gaming-machine-with-an-external-video-card-dock
 
Solution