Right my pedigree chums! my comp is slower than a sleeping snail! how or what can i do to speed it up?

Supposed to have 12mb broad band but only says 2.5 mb when connected. comp say still 57% memory? not clued up on computers so any help would be much appreciated. the computer is genrallly slow normally . says 40gb hard drive, 2.5 gh celeron pro, 128mb ddr? is an emachine . if need more mem anyone know where can get some?
Answer
Would definately suggest more memory. should be able to pick some up at compusa or bestbuy or circuit city. you may need to bring them the model of your pc so they can look up what memory will work. they will need to know more than just emachine. i would try for at least a gig of memory if your machine will support it. so hope this helps.