When I turn on my computer, it gives 5 long, 3 short and 5 long beeps.
This is what I read on Gateway Support:
"1-3-5 - Memory not supported (invalid SPD tCLS or tCAS)"
Does anyone know what this means, and how I can solve this?

try to adjust bus speed of memory in bios or try another ram module

Hi,

First go to your bios and make sure your fsb setting is set to its normal setting. Then make sure all the settings for your memory are set to auto.If is still not booting take all the sticks out, but leave one in the first memory slot. If the system still won't boot take out the stick and try another. If one stick dosn't work then that stick may be bad. If all the sticks work by themselves then you might have a compatability issue with one or more of sticks being a different speed or different latency(cls cas)usally 2,2.5,or 3. Look at numbers on the sticks to make sure there the same. If they are, your motherboard may have a bad memory slot.
Feel free to post more information.