If you already know the motherboard’s code name (visible by running wmic baseboard get product,manufacturer,version in Command Prompt), search that name plus “HP Maintenance & Service Guide” on HP’s site. For example: “HP Erica motherboard service guide” .
HP often uses proprietary mounting mechanisms for CPU coolers. The manual provides the socket type (e.g., LGA 1200, AM4) and the specific thermal design power (TDP) limits. This ensures you don’t buy a CPU that the motherboard cannot support or a cooler that physically won't fit inside the HP chassis clearance. hp motherboard manuals