Dell xp sp3 os 32 bits

My computer is running at a snails pace. I think I do all the right things. I do the updates daily, have a security suite through my internet provider, cleanup disk, defrag weekly, run ccleaner at the time of startup of system. Maybe I need more RAM, currently have 1.25GB. I think my operating system can handle 3 correct? What else can I do to optimize my system?? When I am on the internet I constantly freeze up. Any suggestions are appreciated.

Leslie