hi. i downloaded the mmo , ddo. i do not know alot of computer terms. when i go to run the program, it tells me sse is required and to consult my motherboard to enable sse. i dont know what sse means or where to go to enable my sse. can you help?

If you got a request to do this then it is more than likely that your system is old and it is not installed. This is true to the older versions of PIIand PIII chipsets.
It is actually controlled by your graphics and may be possible to try updating the graphics within your system to a newer/faster graphics card. If your system does not support this upgrade then you may have to just opt to looking at not playing Dungeons and Dragons online as a massively multiplayer onlinegame.

Wikipedia article about SSE:

Streaming SIMD Extensions - Wikipedia, the free encyclopedia