A quick glance says the system is well used for surfing and games.

You have a few things I'd kill but that you might not mind. (wildtangent, etc.)
Cacheboost probably isn't doing anything useful.
You have both norton speeddisk and diskeeper. Pick one. DK is better. I prefer PerfectDisk over both.
If it were mine, I'd uninstall all of Norton & use alternatives. It is not resource friendly.