OK, so I bought a new video card and power supply for my computer. It's a Lenovo IdeaCentre K430, and the power supply I bought for it is a 600W. Now bear in mind, I troubleshot this to the best of my ability, but no matter what I try, when the new graphics card is plugged in with the PCI-E port occupied from the power supply, it just won't leave the boot up screen showing the computers maker, Lenovo, while giving a single beep every moment. It works fine with my old GT 620 card and even with the onboard HDMI port, but the new card. Computer says "Nope." Any help?
Added (1). Forgot to add this is a Windows 7 PC. There's no Secure Boot setting in the BIOS as there would a Windows 8/8.1 PC would
Added (2). OK, so I took it to a tech at my old job and we tried everything. What finally worked was upgrading the PC to Windows 8… I don't like it, but if it means better graphics, then I will deal for now.