I have a DELL OPTIPLEX 745 and I accidentally pulled out my Graphics card while my computer was on and it crashed. It wouldn't switch on, the HDD was just making a slight noise and then it stops. Eventually it was switching on but was giving an error that says, " Boot device A, could not be found, Press F1 to try again and F2 to enter setup". if I pressed F1 then it wouldn't boot up. When I go into the Bios, under the Drives TAB, it shows that SATA Drive A is not present.So I then re-installed my operating system ( Windows 7 ) and it still does the same thing but now it gives me an option to Press F12 and then i can select to Boot from the HDD and then it loads my OS. Can someone help me to fix it so that it starts up normally or reset the Bios or something like that?