He's right about that, your system is based on hardware a few generation older than the current mainstream,
I looked up your basic specs real quick, and for one that board runs DDR1 which is getting harder and harder to find and you could get double the performance from DDR2 for a lot less money,
also your motherboard is more than likely socket 478 the original P4 socket, which you'll be hard pressed to find a decent processor for.
the best you could get would be a pentium 4 3.0Ghz from newegg, for 79.99, however for a little bit more money you could get a much better dual core on socket 775, if you were willing to upgrade your board.
I just recently upgraded from a P4 system, I looked down every avenue I could to make it formidable, I even payed about 300 dollars a year and a half ago to buy 7800GS AGP card, that gets lapped by lower rated PCI-E cards. It was time for me to make that jump, now
it may be time for you. eventually you get to a point you have to change the baseline.