I installed Partition Manager from 7Tools on my computer, then I proceeded to change partition size and merge. It gave me a warning about LILO would have to be overwritten, or something like that. Anyways. The result was that I lost GRUB. I managed to reinstall it. But then to my horror, I could not longer boot up to Windows XP. I have another partition Windows server 2003 that still works and resides on disk C. As for the RedHat partition, I deleted it since it seemed to cause trouble. But solved nothing. I put the Windows XP CD in the drive, and booted with it in the Recovery mode. I typed fixmbr, and that got rid of GRUB and gave me a list of the two Windows O/S mentioned above. But like I said, I can only boot to Windows server 2003. So I rebooted in recovery mode, and tried the command bootcfg /rebuild. It found the Windows server 2003 partition, but not the Windows XP partition. So I tried the fixboot D: (XP is on drive D). That fixed nothing.
By the way, when I try to boot to Windows XP, it gives me an error that the file ntoskrnl.exe is damaged or missing. So I went in the boot.ini file, and changed the disk(X) parameter where I tried X=2,3,4,5. It solved nothing. I also tried to reinstall that file with the expand command such as expand /F:ntoskrnl.exe sp2.cab, but that solved nothing.
At this time, I am stuck. I have a big web site that sits on the Windows XP partition (I have a backup but not the latest). I don't want to have to reinstall Windows XP, and fear to loose that web site.