It would help to know what specific HP model you have AND the form factor(ie mini tower/desktop/small form factor). That's because these kinds of computers can be configured in many ways. Simply knowing the motherboard isn't enough. One thing to know, the 1156 socket pre-dates the widespread use of the UEFI bios, which the new Nvidia cards tend to require. Some pre-built computers may also have bios limitations where videocard upgrades are concerned, among other reasons because the motherboard might not provide a standard 75W of power.