hey, i've inherited an optiplex gx240. it's got a p4 1.8 ghz processor in it. the socket reads 478 and the processor reads 1.8A GHZ/512/400/1.5V so im assuming its a 512k onboard cache and 400mhz fsb. im gonna use the pc to connect to the tv using xp and media portal and it runs ok if a little sluggish. what can i upgrade the cpu to? can i go or a higher ghz and 533mhz fsb? cheers.