I'm posting this to share what I've learned this weekend, in case anyone else here runs into the same issue with putting a gpu in a store bought PC.
So my brother has a HP Pavillion with an AMD A10-5700 apu in it. Over the past two years I've put a few upgrades in it for holidays and his birthday, being the awesome bro I am. I've put faster ram in it, a 500w modular Corsair psu, and now a Sapphire Radeon R9 270x. (A Fractal Design Core 1000 case is on the way this week)
So the graphics card was the nightmare I dealt with this weekend. Long story short, it was on HPs end being an incompatibility with HPs UEFI Secure Boot . I fixed the problem by disabling Secure Boot, and enabling Legacy mode.
So it started after I installed the gpu, couldn't get a display out of it or out of the onboard while the gpu was installed, and the pc would beep 6 short beeps equal in length and space apart. Like an idiot, I ignored the beeps and focused on WHY IS THERE NO DISPLAY, RAWR. So a few hours of switching between the onboard vga, the gpus hdmi, then both of them plugged in, downloading drivers and catalyst control for both the gpu and apu, switching between the onboard and gpu again, taking the gpu out, disabling the apu graphics driver and doing everything over again, try with my own gpu and do everything over again and i had no success. One time it actually worked for a bit, dont know which driver actually worked, but I got a display. Then I was like, ok now i have to install the real ones for the gpu. So what do I do? I use AMDs cleanuninstall utility. The display went out after it deleted whichever driver it was. So I spent another hour trying to recreate what I had done without success, so I rage quit for the night.
Woke up the next day and went at it again. This time, I played around a bit trying to recreate what I had done again after I had cleaned out duplicates of everything I downloaded. Then I decided well I should really look up what those six beeps mean. Looked up six beeps no gpu display, and a few results down, I seen something about another guy having the same issue with an HP. One comment on the post said to go into bios first and switch from Secure Boot to Legacy. I wasn't sure it would work or not, but this was going to be the last thing I do before I order a new motherboard and cpu and sell off the apu. So I fiddled around in the bios for about 15 minutes just looking at everything, seeing whats what since it was the first time I had actually seen this PCs bios. Then I figured out what I had to switch, switched it over, saved and applied changes, booted, shut down, installed the gpu, and rebooted. I had finally gotten a display. Installed the drivers with no problem, ran a session of skyrim, everything went well.
So for those who might have encountered this problem and haven't found a solution yet, or are just now encountering, just switch to Legacy in bios. Or just don't let a bro buy a store PC.