Hi, and welcome to anandtech.
I am gathering you made a motherboard change, used your current hardware and tranfered them to the new board correct?
If this is true, and by tranfering some questions from you are needed.
Are you doing a fresh install or are you trying to use the original installed OS that you have on your HD?
Because you are transfering from a HP PC, this will be a bit of a challenge for you and you might have to make some sacrifices along the way.
So, with that being said, you might want to start by replacing all that you have back to original by using your HP mobo and if it all boots correctly, then we might have a chance here. If you want to save your OS, you will have to uninstall ALL hp devices and software from your HD from within "control panel" and "Device manager" from the property section in "my computer".
What is probably happening from your change is that your new motherboard does not reconize all the hardware (drivers) and some of the software (drivers) from within and you have to delete them before you make the switch. But be advised, you have to delete all the drivers to the HDD etc and do not reboot until you have removed all. Make sure before you shut down you have done your homework and removed these devices.
When you transfer your hardware back to the new mobo, just use 1 stick of ram, your HD, mouse, keyboard and your DVD. Make sure you have all plugs in the correct spot and when all is doublechecked, Boot and get into Bios and make sure your HDD and DVD is reconized and the boot order is to DVD first. then when this has been completed, hopefully it will boot into your OS. You WILL have to have your new mobo drivers disk to install the appropriate drivers.
If you want to do a fresh install, disreguard all the driver removal and get into BIOS of your mobo, make sure you have all your drives reconized and in the boot order and then boot. You will need your OS and drivers disk. Good luck!