I had Win2K and Red Hat 9 dual booting on a hard disk which was using grub. I tried to repartition the disk using Partition Magic and deleted the Linux partition as I was going to re-intstall it. I was trying to also add a partition for Windows XP so that I could have the 3 OS running together. Now Win2k will not boot and the system hangs at grub prompt. I do not want to lose the data I had on Win 2K and would like to know how I can get it to boot since grub is still trying to take over and linux is now gone. How can I access MBR and edit it to boot the Win 2K.

boot to w2k CD and use the console repair function, where you can type "fixmbr" at the command prompt to fix the w2k master boot record.

boot to the emergency floppy you made when installing Win2k (you did make one right? )
at the prompt type: fdisk /mbr

unfortunately I did not make an emergency floppy. can I make one on another computer that has Win 98 without having to install Win2K on it since I have the setup CD. I also get an error that "the file disk.sys is corrupted" when I boot from Win2K setup disk. I have a Win 98 boot disk and also a Win XP setup disk. Can any of these work?

If it is Win98 SE (second edition) it will work. The first edition fdisk did not have the /mbr switch. The XP (experimental project) disk should also work as it evolved from Win2K.
I should add that when you run this command it won't look like it did anything. It will just return to the prompt, then remove the disk and reboot.

boot disk did not work. would you recommend trying to re-install Linux.

try here:

www.bootdisk.com