GRUB and WIndows XP

[André Heßling]

Hi!

I have Red Hat 8 and a few days ago I was using Windows 2000 just fine
using GRUB as the boot manager. But suddenly ntldr was missing.
I tried fixmbr and fixboot from the Win2000 recovery console but no
chance. Of course, fixmbr has written the original boot manager from
Win2000 and so GRUB was out of the MBR.
So I booted from the Red Hat CD into a rescue console and used
grub-install /dev/hda1 in order to rewrite GRUB into the MBR.
On /dev/hda1 Windows is installed.
/dev/hdb is the Linux harddisk.
GRUB now works, but if I try to boot Windows 2000 the screen flashes and
again the GRUB menu is there. At least I expectated that ntldr would be
missing. Now I can't get access to /dev/hda1 (NTFS) from Linux, either.

But this is not the real problem because Windows 2000 was getting a
little bit slow, etc. So now I want to format C: (/dev/hda1) and
install Windows XP on /dev/hda2 (D:), because on D: there is more space
left. C: is then used for something else.

After the Windows XP install I will get the Windows XP boot manager so
that I can't boot Linux any longer. To fix this I thought I could use
/sbin/grub-install.
But now I am afraid that grub-install will damage the MBR again, so that
I can't boot Windows XP and therefore only Linux (just like it's now).

So my questions:
If I am going to install Windows XP to /dev/hda2, will the MBR of WinXP 
still be on /dev/hda1?
What is the proper use of grub-install? I think that there has occured a
problem using "grub-install /dev/hda1" and maybe it damaged this
partition.
I know it must work because the Red Hat setup wrote GRUB properly and
made the config file so that I was able to boot Linux AND Windows
without touching anything.

Thanks!
-- 
Regards,
  André