My mother'n laws computer is running much slower then it should?

I have cleared history and temp, defraged, boosted her ram (1 gig ddr to 1.5 gigs ddr may boost to 2 if fear2 still has to many issues) just switched her vision tek raidon x1550 for a geforce 6200, (as she wants to play fear 2 and thats the closest I could get and it does work for it if run on minimum.) she has a P4 3.04. i know its a slower comp by nature (compared to the new 64 bit runners) but if i could do Oblivion on lower stats (my comp lol) it should not be crawling she is useing zone alarm for a firewall i have no exp with it as im an avast antivirus fan and do alot of downloads( torrents ). is there a chance if i being her registry ( though no errors are poping ) if so can you name a free program that actually works. or any other types or advice my christmas gift is a full monty fix and speed up of her comp. oh yeah shes on xp sp2 might be three as they added it to the auto update list.