You could try but the truth is you are likely to run into problems because HP never created Windows 7 drivers for that computer. This means some components might not be seen by W7 and if that is the case you might not get anything but basic video, maybe no networking (LAN and/or Wireless), no touchpad, etc ... whatever drivers that can't be supplied by the W7 default drivers wouldn't work. You might get lucky but it is a lot of work for a slim chance.
I know everything is a bit different in Win8 but the biggest difference is the Metro interface instead of the Start Menu. For my customers migrating from W7 I install the freeware
Classic Shell (and actually I only install the Start Menu portion, not the changes to windows or internet explorer or the automatic updater) and the rest of their transition to Windows 8 seems to go quite smoothly. I would encourage you to give Windows 8 along with Classic Shell a try first. Note: Once installed there is even an option in the Classic Shell settings to bypass the metro window completely and go straight to the desktop on login if you wish.