Which dell pc did you have? 1) 1st try use the onboard iGPU if your dell pc has one. Boot into the BIOS, in graphics section, set the option to either auto or pcie, or disable the onboard iGPU, save and exit. Reboot the PC. 2) maybe the PSU has lower power to power the hd7470. 3) you may need to update the BIOS for the hd 7470. 4) If the dell pc is too old, the gpu may not be compatible to that dell pc.