I have a HP pavilion p6-2204a which comes with a GT 630, and recently i decided to upgrade it to a GTX 750. So I went out and bought the card, and tried to install it myself. Unfortunately the system stucks forever on the windows 7 logo screen. I swapped back to the old GT 630 and everything is fine. I installed the driver for GTX 750 with GT 630 on board and kept trying, and now with the GTX 750 on board, the system gives a short beep for 3 times with ~20 seconds spacing between them, and the screen doesn't give any signal after this. After some research I realised this might be the secure boot problem, but I cannot find a secure boot option in bios (AMI 7.07). Has anyone encounterd similar situations or does anyone knows how to fix this? Any suggestion is appreciated.