Reinstalling just the kernel in Fedora

[Liz Hare]

Hi, all,

It's been about two years since I installed Fedora and I'm pretty rusty on understanding how the kernel works.  I think I need the help of a Fedora expert (Janina? Bill?).

I have a dual boot system with Windows XP and FC 4.  It stopped working recently, and the memory, motherboard, and processor have been replaced.

I know I had a 64-bit processor.  I wasn't here when the dell guy replaced the parts, but I think I no longer have a 64-bit processor (grrr).  Windows just says Intel Pentium 4 CPU (2.8 GHz).

I had both 32 and 64 bit Linux distributions.

Now, when I try to run the 32-bit distribution, it tells me long format is not supported and I need to run a 32 bit distribution.  Not sure why this is, but it looks like I have to reinstall the kernel.  Of course, I'd rather not have to reinstall everything from scratch, since I have installed and compiled a lot of genetics and statistical software.

Is it possible to reinstall only the kernel?  I seem to remember that the install process didn't let you stop after only doing some of it, and that you could lose information you already had in your /home directory.

Any thoughts?

Thanks, 
Liz