PCI-E = PCI Express
People were probably telling you to avoid AGP cards because they will be phased out one of these says, as will regular PCI slots.
There is really no way around it, if you want to get a decent, up to date graphics card, you will atleast need a new mother board, and you'll probably need a new case too unless you buy the motherboard from HP, because I doubt you'll find a motherboard that has outputs in the same lay out as the HP case was designed for.
People were probably telling you to avoid AGP cards because they will be phased out one of these says, as will regular PCI slots.
There is really no way around it, if you want to get a decent, up to date graphics card, you will atleast need a new mother board, and you'll probably need a new case too unless you buy the motherboard from HP, because I doubt you'll find a motherboard that has outputs in the same lay out as the HP case was designed for.