I'm pretty sure the new card disabled the on-board one i can't find it anywhere on my computer except in windows updates and i tried to update it and it failed and said it didn't exist or wasn't plugged in, but if i take the new card out it works just fine
They should both be listed in device manager under display adapters. You should only have one display plugged in, and usually on the motherboards output. If you haven't already, try using the latest catalyst drivers. If you still aren't getting both being recognized as devices, see if there's any way to flash the BIOS. If you've never updated a BIOS before, follow the instructions carefully, a corrupt BIOS is bad.
What's the model number of the HP?