If POST Beep Codes Indicate a Memory Failure
If you turn on your computer and the POST beep error code indicates a memory or RAM problem, then there are several steps you can take to determine if you are going to need to replace all your RAM, part of it, or if the problem is actually the motherboard.
If you are not sure if your POST beep code is implicating your memory, this guide will help you interpret the code and find out.
All of these troubleshooting steps are going to involve you rolling up your sleeves and getting your hands inside your computer. If you're not comfortable doing this, then you're better off taking your computer to a professional. These steps, though, aren't very difficult and the chances of you "messing up and breaking something" are quite low. Just follow my instructions and heed my warnings.
The absolute easiest way to determine if your RAM is the source of your computer woes is to simply replace it with RAM that you know is good, by pulling it out of another computer, borrowing it from a friend, whichever you choose. However, there are risks. If you put incompatible RAM in a slot intended for a different voltage or speed, it won't work and it could damage your RAM. Also, if the motherboard is the real cause of the problem it could take your "good RAM" and very quickly turn it into "bad RAM".
The safer (and still easy) method is to take the RAM you suspect as being bad and putting it into a motherboard that you know is good. Again, assuring compatibility is key. There is a much lower chance of RAM damaging a Motherboard than the other way around.
If extra RAM and/or motherboards are not available to you, don't fret. There are still ways you can narrow down the problem before you go running out to the store to buy new RAM.