Darjian :
basically, my computer won't start because it needs two sticks of RAM?
You have to forgive scout_03 and smorizio's grammar, they are hard to understand sometimes.
What they are trying to say is be sure that the 1 memory module you do have is in the first slot on the motherboard. You should be able to find this by looking at the motherboard and they typically are labeled either via color coding or on the board itself. The first slot is going to be closest to the processor.
As for running with only 1 DIMM, yes it will work when installed correctly but you will get better performance with having a 2nd DIMM in the corresponding channel to this one (hence dual channel configuration) especially if you are running x64.
I'm going to take a look at your motherboard specs and get you the exact type of configuration.
EDIT:
Your motherboard slots should be blue and black consecutively. Be sure your memory is in the first blue slot closest to the processor and don't force it in. When you push it in the clips should be pointing outward and as you press the memory down into it the clips will close up around it.
If you've got it installed and are getting beep codes, then those are typically memory beep codes and could indicate DOA memory. Did you make sure that the memory is compatible with the motherboard when you purchased it?
EDIT 2:
I would also make sure that your memory appears on the qualified vendor list found
HERE .