2 monitors from 1 output

i have bought a cable which connects to the monitor output on my geforce mx 440 64 mb videocard, and hooks up to 2 monitors. unfortunately, the videocard doesnt seem to realise there is 2 monitors hooked up, so i cannot drag windows between them, i only get a clone. i have seen this done b4, however, have tried everything i can think of and have run out of ideas. if anyone knows what im doing wrong, i would greatly appreciate some advice. thanx

I’m not sure but I believe that you need 2 vga output to make that

Read about the twin view on nvidias site…theres have some pdf that can explain that