So, i bought a PC about a month ago, without a video cardv(so PCI-E slot was never checked). Used iGPU for a month until a couple days back i bought a PCI-E card(r9 290) and when i inserted it and tried to boot i already started to have problems - i couldn't boot PC at all (everything turns on, fans, GPU fans, but no beeps or anything from BIOS - just nothing loads, and i can turn off PC instantly with power button, i don't need to hold it or anything like if you would when your system is freezed). Tried re-inserting the card, and next time it somehow booted - but i couldn't see the video until windows started to load, and then i just saw 1 picture of my desktop (just the picture, no icons or anything) and thats' it (but everything in windows was loaded), so i had to manually shutdown the PC. Or, when it boots, it somehow just shows things in slideshow (literally) - like when BIOS are loading, they are loading one frame at a time. So i decided to start windows on iGPU and tried to check via GPU-Z the card - but GPU-Z showed strange numbers - most of them were unknown, and the other ones wasn't like my card specs. So i thought that it's probably the GPU is faulty or PCI-E slot.. I had an old PCI-E card with no external power source which i knew worked (at least, then) and thought i could check if it maybe worked. But i've ran into problems too - i couldn't boot normally - i almost always (but not every time) could get to POST (that was different - with new card i almost never could) but it always hangs when windows are loading, though video is not disappearing - the PC just hangs and then i need to manually shutdown the PC. When it somehow passes that part were it hangs and loads to windows, then video just disappears and PC hangs again. The PCI-E slot looks good (no bent pins or anything, but i didn't check with magnifier), though the slot somehow tilts the card to the side when the locker locks the card in..But i don't think that could be problem because i tried the old card inserting several ways(when locker locked and card tilted, without locker but card is straight), but there are always same problems. So.. what could this be? Bad PCI-E slot? Both cards are faulty? Bad motherboard? Bad seated CPU? While using PC for a month with iGPU i never had any problems at all.