optimum-fireworks

Hi All and my apologies as a forum admin elsewhere for the standard "my problems is" post I have a standard dvr (generic) with 8 inputs and believed one or more of the cameras to already be HD, Ive just purchased more Floureon 2mp cameras and none work on the system, the IR leds illuminate when the sensor is covered but no image is shown on the screen whatever I do, replacing with an old camera shows an image immediately though Im therefore thinking after googling that my system is either not HD compatible (IE im wrong an existing camera is HD) or I simply cant find the settings to up the resolution of inputs? Could anyone either assist with what to look for in the settings or tell me Im fighting a loosing battle as my system simply isn't compatible? I will go and find details of the cameras and DVR when I return home as I assume this will help greatly!

Thanks for the reply, what should i look at purchasing specifically to suit the cameras?