Graphics card update problems

[Hyperpatrick]

Im having problems with my compaq pc..
I've been trying to play some games on steam (GTA 4, CS:GO, Etc) And they all require a shader model of at least 3.0.
Heres where i run into the problem, my PC is a compaq Presario SR5410F Desktop PC. And the smart people at compaq decided that my graphics card should be integrated into the system.

Is there any way to update my graphics card without literally buying a new PC?

Just for help, heres my PC specs.

Spoiler

http://h10010.www1.hp.com/wwpc/ca/en/ho/WF06b/12132708-12133156-78308260-78308260-78308260-81670541-81871247.html?dnr=1

 

[DXRick]

I wouldn't bother with that system. Even if you found that the motherboard has an available PCIe 16x slot, and the case has enough room to fit a new GPU, there is no chance the PSU will have enough power for it.

 

[Hyperpatrick]

Alright, i guess im getting a new PC xD
Thanks!