I tried installing it into my computer's pcie x16 slot, the card's fan is spinning but it just freezes at the blue hp screen saying "press esc to access startup menu"
tyr to use one ram module and see how it does could be something else that prevent her from working also do you still have your old gpu on hand did you remove the old driver .
no leave it on at least you have video with it on the system but try to test that gtx 750 she could be defective and if you could try another card in the gpu slot for the video .