@Mohsin420 , welcome to the Community.
Here is the Maintenance and Service Guide for the computer: http://h10032.www1.hp.com/ctg/Manual/c04224518.pdf
If you look at the section titled "Misc Boards" on Page 52 there is a list of compatible video cards. I checked and all of them are low-profile. A standard card will not fit into the case. Also, you will have to check the wattage of the power supply unit (PSU) to assure that it will be sufficient for any card that you buy. It is 240W. This would not power any of the newer cards. The minimum is 300W. I believe that HP's motherboard is proprietary.

I am not an HP Employee!!Intelligence is God given. Wisdom is the sum of our mistakes!!