I believe in rewarding anyone who thinks of backing up.
1) Lots of ways to back up
The easiest in the long run is software from
www.partimage.org which is on most good rescue cds such as knoppix or rescue cd. I prefer
www.sysresccd.org.
b) backing up your mbr happens with each image you take with partimage.
c) but simpler, you can use dd to save mbr to a floppy.
d) there are of course propiertary code to back up and I was using windows ghost which is still a fine program.
GRUB
I am not sure of your question so let me waffle on to soothe a savaged soul. GRUB can either be in your mbr and so IS your primary boot loader and as you mention RHAT I suspect thats what you had on first boot up ?
But Grub can also be in a partition, why why its too good to be left there but anyhow its your choose. But then you have to be using someother boot loader like lilo or smartbootmanager?
WILL IT ERASE XP
Gosh I know grub and it can not erase a partition unless you have used commands and I suspect you don't know how. You mention clean up. Does that not suggest your problem is with XP and maybe you should avoid the target of most virus and spyware writers?
I have written a tutorial on how to install grub etc if you are interested in staying with GRUB.
If your redhat rescue floppy was a true grub floppy then you can use most of those commands in your menu.lst (etc/grub.conf) file