Hi
i have both Linux and Windows XP on my PC.
i used to use grub as a boot loader and everything was perfect, until
i reinstalled Windows.
apparently, Windows installer installed its own bootloader, that
doesn't recognize Linux.

i tried using a tool called GrubInstaller for Windows, and now i can
choose to boot either "Windows" or "Grub" OS, but when i choose Grub,
i get a grub-command-line shell, and i don't know how (and don't want)
to use it to load my Linux.

I tried to reinstall Grub using my Redhat installation CD, but on the
screen i should choose the operating system to update (or install a
new one), i choose my Linux installation, press OK, and get an error:

"Error enabling swap device hda6: invalid argument. This most likely
means this swap partition has not been initialized."

so my questions are:
1) how can i make NT boot loader load my Linux installation
2) how can i install Grub from Windows?
3) is the swap-device problem related to this issue? or will i still
have this problem once i get a bootloader to load Linux?

tx in advance

Try to find some information in the docs.

what docs?

I'm not sure of the solution you are looking for..

But in future, before installing windows take a back up of MBR because windows always overwrites the MBR and we can't see linux bootup at all. If you have back up, after windows installation you can restore the old MBR .

any solution you can suggest, that doesn't involve reinstalling an OS
i don't have a MBR backup

is there a way to install GRUB from Windows, and make it recognize my Linux?