Can I put a GeForce 9800 GT in a hp compaq dc7800 computer that hasn't had any upgrades done to it?

[turgutcosan]

I want to play a couple games on Steam and I have to get a better GPU

 

[Dragos Manea]

Instead of putting the name of your pc, put a link so to know for sure what to suggest you, i can see there are 2 type vertical case adn orizontal case. PLease post link to your pc, i dont think is to hard to search on google.

Also specify what 9800 gt, there different size depends on cooling.