I have a HP Pavilion how can I get it to run minecraft without a promlem?

Its a Notebook Computer what type of thing would I need to do to make it run games better, or should I just buy a 400$ or 500$ PC that can run those thing easily.

You would need a better graphics card, RAM, and more storage first off.

Since you give no specific details other than a brand sticker, there's no way to know what you have and what it can do. If it was a low cost PC at the time, and over 4 years old, it is time for a new one even to just play Minecraft. I believe a core i3 with HD 3000 can handle Minecraft or possibly some of the A6 and A8 AMD based laptops. You can probably get in at under $400 by a little.
This $350 one is enough, not to say there are not others that can do it:
http://www.newegg.com/...6834312827
http://www.game-debate.com/...quirements

Newegg collects sales tax in CA, NJ, TN
HP brand in general does not impress any more.
http://www.rescuecom.com/...13-Q3.aspx

Add: Can't upgrade laptop graphics or CPU typically, and more ram is generally not the issue.