xGod of Zunex
Is it possible to replace or dissamsemble the motherboard of my old intel pentium 4 cpu for another motherboard of better capacity and power? Example: Intel Core 3, amd, etc
Yes, but you'll also be replacing the CPU and memory in the process. (The P4 and the RAM you already have won't work.)
xGod of Zunex
Is it worth the cost or not
It's worth just not having one of those damned Pentium 4 CPUs.
xGod of Zunex
I was wondering because I am trying to replace the old processor with its sluggish integrated graphics card with a more decent one
So... you'll be buying a new video card, too.
You'll need to evaluate the system as a whole and decide whether this is going to be feasible to simply replace parts:
If your power supply (the big box with wires coming out) isn't rated to provide enough power, you won't be able to use most new video cards with it. If it's less than 500W, you'll most likely need to replace it.
Since you're basically replacing the whole computer, and you use Windows, you'll need to reinstall to reactivate. You may need to budget for an extra Windows license or consider upgrading if you're not already on Windows 7.
You may as well consider replacing the case as well, and just build a new computer (since there's not much that you're not replacing anyway.) It's not difficult, and it can be cheaper and more rewarding than buying a pre-built system.