Changing the processor is not going to be worth it, but increasing the RAM would probably help. The sites I've quickly looked at suggest it will only have 1GB installed - apparently 4GB can be fitted, but Win7 starter will only "see" a maximum of 2GB.
But even before you consider that, have you had a look at the usual "slow running" suspects, such as unnecessary start up items? There may also be running services that you don't use or need, which can be disabled.
TFP