Know your existing graphics card
The first thing you should know is the name of the graphics card in your system unit.To determine your card by clicking on Start, Control Panel, and choosing Appearance and Themes.
Step2
Before installing your new card,delete any software and the old device driver for the old card.To remove this file,click on Start, Control Panel, click on Add and Remove programs.Now look for any references to your graphics card.
Step3
Find the entry for graphics or display device and change the setting to disable or off.After this you save the changes and exit.