BlueStacks require your computer to have a graphic card and RAM of about 2GB. If it fails to find a graphic card then it issues this error message.
NOTE: If you have a very old PC it might not have the graphics card that can run OpenGL and thus Android won’t run on it.
Now the problem is your computer may be having a graphic card, however its drivers are outdated.
BlueStacks is not able to recognize your graphic card and what you need to do is update your Graphic Card (Display) drivers.
Do as mentioned below:
1) Open My Computer and right click on Computer icon on d left side and select Properties...
2) Now, click on Device Manager on d left top of the window...
3) Now, a new window will be opened as below...
4) Click on left arrow of the Display Adapters in the window as below and right click on the driver(normally the first option) as below and select update Driver software ....
5) Now.it'll give options like 'automatically update it from internet' or 'from your computer'...
Select 'automatically update it from internet' and it'll try to update your display driver as below....
6) If it goes normally, your problem will be solved...
7) If it doesn't, go to your Graphics Driver site (AMD/ NVIDIA) and dowload the latest driver of yours...
8) After that, select the 2nd option "Browse my computer..." instead of "automatically searc...." as below....
9) Now, browse the location in which the downloaded driver is present n select it....it'll be installed and your problem will be solved..
Dats it... :)