First look at where you are placing the first AP/Router. If it has a weak signal due to walls and other obstuctions you will need more repeaters. Make sure the antennas are pointed away from each other and also move it higher up as the signal falls like the top of an umbrella.
What video card are you using? Check if the driver to the VC has been updated. We had an issue where the driver only went to win 8 so we installed a generic for a different card under the same brand and it came up.