I have a pentium 4 processor in a 32 bit machine. I understand the processor plug/sockets all differ, what do you think would fit in there?

Maybe a slightly faster Pentium 4 is all you'd be able to put in the motherboard.

Intel changes their sockets every couple years. If you use a program like Speccy it can show you your motherboard specs and you can find out what socket you have. Intel's sockets aren't backwards compatible generally.

Then you can find out what your motherboard supports... but it's probably not worth the money to find a good used P4 cpu, you'll probably only get 5% or so faster speed.

There would be nothing worthwhile upgrading to, even the very fastest CPU you could fit (and keep in mind older LGA 775 boards often do not support the later LGA Conroe or Kentsfield CPUs') will be totally obsolete by modern standards.

You're going to be much better off saving up for a new computer.

that thing is donkey's years old now. all you can do is look up the mother board's specs and see what other processors, if any, it supports.

my guess is there;ll be very little you can do

essentially replacing a mobo is getting a new PC. look up the mobo model or if its a prebuilt look up the make and model (like dell dimension 4800 max cpu.)

Nothing worthwhile! You can't polish a turd!!