Your Windows installation was configured during setup for the hardware of your HP and would not run using the hardware of your MPB. That does not mean you cannot get the data. Simply purchase a USB drive enclosure (without a drive already inside) and put your old drive inside and use it like any other external USB drive.
Laptops have 2.5" drives and desktops (your HP?) have 3.5" drives. Also there are IDE and SATA type drive/enclosures and you need to buy the proper one. Your SATA drive won't go in a IDE enclosure. Since you said it was a Windows 7 PC it's easy to assume it was a SATA hard drive ...but when we assume we...
Remove the drive from the HP and look at the data connection [not the power]. A wide flat ribbon is IDE and a skinny cable is SATA. Enclosures can be cheap online and they make some that can handle both types. Do a Search for -> 3.5 USB enclosure The word "enclosure" being the key word as you will otherwise come up with USB drives that already have drives in them. $20 -$49 Higher than that likely means it has a drive inside that you don't need.
If you are insistent on running the HP on the MPB, try VMWare or some other O/S virtualization product. The HP would have to still be operational to capture a Virtual image.