Make sure video card is properly installed and connected to the motherboard. For details about installing the device you can learn from the instruction to a video card or on the website of its manufacturer. Check for loose cables and verify that the monitor is in working condition and is configured to transmit the video signal.
The problem with that is that the computer "sees" the installed graphics card may be incorrect BIOS settings. Restart or turn on computer and press F2 or DEL to enter the setup menu. Browse the available sections of the BIOS and select the one that matches the settings of the video card. In its title can present words such as Video, Display, Graphic or VGA.
Activate such parameters of the adapter, such as VGA, Video, and Primary Display. Install the tire of your graphics card: PEG, IGD, PCI or AGP. Press F10 to save the settings and restart the computer. After that check whether to start loading the operating system, and in the case of achieving a positive result, make sure that the installed video card is present in the list of connected devices in the computer.
Update your graphics card driver. If you have problems with the image, for example, it is distorted or lost, most likely, the fault is an outdated driver. Start the device Manager through the control panel of the computer. Navigate to the tab with the name of the video card and choose "update driver". Make sure you have an active Internet connection because the driver search will be carried out through it. If the system was unable to find a suitable upgrade, you can boot independently. Open the website of the manufacturer of the video card and go to "Drivers" or "Drivers". Enter the name of your adapter and the version of the operating system, then download the distribution and follow its installation.
Check your operating system for viruses and other malware, using antivirus with updated databases. No images or other problems with it can arise because of contamination of the system. Also there is a possibility that the video card just went out, so you can try to replace it or even just to check on performance, but on another computer.