hi
this is because the vga card in your netbook, eventhough it is intel built-in, is much better than the vga card you have in your p4. also your netbook will have atleast 1gb ram which is much better than the one you have in your p4. also it uses ddr2 ram, while your p4 will have either ddr1 or SD ram. so thats y your p4 is weaker. if you put 1gb ram in p4 and a normal vga card like 8400gs, agp version because i think your p4 will have a gp slot, then it can run blu-ray movies which are the heaviest media currently.