I wonder if you are comparing this Sempron machine to some other faster computer?
I have an eMachine T3306 with an AMD Sempron processor 3300. It had 524mb memory and was running very slow. I recently upgraded memory to 2 gb but it didn't help. I have defragmented the hd and done everything that I could think of to increses the speed. It appears that something is running most of the time but I can't find out what it is. Is there some way to find out what is running or how to speed up the computer.