upgrading

[Chappers]

i have a compaq laptop, its about 1year old and its getting rather slow now,
it has an:

intel celeron
777mhz (runs like 1ghz)
128mb ram

not to sure bout other stuff as it i bought it of somone,it isnt really that good as you can see but im thinking bout upgrading but dont know whether it would be worth it or whether just to completely change it and get a desktop pc, as i can get one much cheaper.

any advice?