From the information you give, you are due to buy a new motherboard alltogether.
I am not sure what you mean by pegs, but if you mean the little white box with a set of tiny dip switch, the instruction for their settings is usually glued or stamped on the casing of the PC.
If it is this; it is to adjust the frequency of your system, but changing the bus speed multiplier. You can use these if you would want to overclock you PC.
If it is some other peg you are talking about, you should use Google or Tom's Hardware Guide to get a picture of your motherboard and find out what you are looking for.
