When you receive POST beeps after installing memory, it generally means there is a compatibility problem with the RAM you've chosen.
If you list the memory you've picked, the make and model of your computer or motherboard then we may be able to help further, however without this information no more recommendations can be made.
You should be able to consult the manual either off the website or the paper version if a physical copy came with the PC/Motherboard. You are looking for the POST beep codes for the motherboard which will have a table listing the codes with what they mean. In your case it's highly probable that the motherboard is complaining about the memory.
You can attempt a different slot or if you are using both sticks to only try the 8GB to see if its the combination of the two that PC doesn't like.
Beyond that more information is needed.