|"ATI mobility radeon HD 4250"|
Gaming relies heavily on graphics & the weak HD 4250 is what's holding you back. Unfortunately, there's nothing you can do about it. You either have to live with it, or buy a gaming laptop, or buy (or build) a gaming desktop computer. Generally speaking, a gaming desktop machine, if you build it yourself, should cost significantly less than a gaming laptop.
Here's some info about the HD 4250: