Although it's not exactly clear, it appears like you installed a new graphics card, then performed a reformat and reinstall of your operating system. After that, your computer would not start up correctly. Is that correct?
Please give us the operating system you're trying to install.. Does the computer have a brand name and model number? Did you install all the correct hardware drivers for the motherboard, graphics card, video card, etc.?
Are you using brand name "Recovery Discs" or are you using a standard operating system disc for formatting and installing the OS?
Please describe EXACTLY what you've done to get to where you are now.
And at this point, have you tried placing the operating system disc in the drive AGAIN, then deleting the current partition AGAIN, then formatting and reinstalling everything one more time?
Hope this helps and let us know more.
i just change mine graphic card n i been using it like 3 day. after it i do a reformat. but i cannot complete n gif me a black screen. now when i on mine computer nth appear on mine screen n no beep sound when i on mine cpu wat is the problem mobo? psu or graphic card?