Try the motherboard or computer manufacturer website... if you don't know the exact motherboard model, install Speccy to see it. With that info search in the manufacturer website and motherboard model page and you'll see a link to the downloads of Drivers, BIOS and manuals. Make sure to install the Chipset and Display drivers to try and solve the problem. If you don't have display, tap F8 every second after the BIOS post, and highlight the VGA Mode or the Safe Mode options, and press Enter to logon and update the chipset and display drivers.
http://www.piriform.com/speccy