I recently bought one 4GB stick of ram from Ebay - 'Corsair Vengeance CMZ16GX3M4A1600C9' however when I have put it in, the computer has blue screened 1 - 5 mins upon starting up. I have tried mixing it with my original ram Corsair XMS3 3x2GB and also taken my original ram out and had the 4GB stick on its own and either way it blue screens. Please tell me if it's because the 4GB stick must come as a 4 for a total of 16GB or if the ram is just faulty. Thanks in advance.