Do you have a lot of stuff running in the background? turn off unnecessary apps in your task bar. At your own risk, turning off things like One Access Virus scanning should improve speed.
Also, the DVD player is probably IDE... If its on the same ribbon as the Hard Drive your operating system is on, they're both competing for its use. I would put the DVD on the Secondary IDE and the HD on the Primary. That way they can communicate simultaneously.
Value Ram... tsk tsk.