I am having problems with dual boot after I installed Redhat Enterprise Linux WS.

I had 2 drives: /dev/hda1 and /dev/hdb.
hda1 had 1 partition wholly dedicated to windows XP.
hdb (80GB) had 1 partition of 30GB dedicated to same XP as a 2nd logical drive. The 50GB was unallocated. I did the following now.

/dev/hdb1 1-3979 orig windows fat32
/dev/hdb2 3979-5284 - Primary Partition (ext3) for /usr
/dev/hdb3 5285-7634 - Extended Partition
/dev/hdb4 5285-5415 - Logical swap
/dev/hdb6 5416-5428 - Logical /boot
/dev/hdb7 5429-7634 - Logical (ext3) for /

In other words from the remaining 50GB I created a new primary partition to be used under linux for /usr and one extended partition for the linux installation. This extended partition was broken into logical partitions for use for boot, swap and /.

Next, under the installation, I picked the option to use GRUB as boot loader and to install boot loader record on MBR.
Installation of Linux completed OK and on reboot, I got the 2 options for booting.
On picking Linux, it boots perfectly. On picking DOS option on the boot loader, I get the following error message
root noverify (hd1,0)
chainloader +1
Invalid system disk
replace the disk and press any key.

I used, fdisk under linux and checked that the hda and hdb1 partions are still there (not erased).

I am a little new to this boot loader stuff; I would really appreciate any assistance on this.
Thank you very much!
-sanjeev

If I read your post correctly, xp is installed in hda1, and hdb1 is just additional space for xp to store files, but doesn't contain a bootable xp installation.

With xp installed in hda1, you should change the rootnoverify line to rootnoverify (hd0,0).

Thanks for your reply. Your assumption is correct. I did that, still I get the same error.
What about the disk swapping commands in grub.conf?
Has the xp partition somehow become hidden?
Thanks.

I changed to rootverify(hd0,0) chainloader +1 makeactive boot

I get Error 25: Disk read error
Please help. I am totally stuck.
appreciatively.
-st