I've posted a couple different threads about this same problem but my friend was trying to help me and he suggested that I copy and paste the GRUB menu commands and ask what's wrong with it ; he also mentioned that I ask how I would edit. The GRUB menu commands are as follows :

timeout 15
color cyan/blue white/blue
foreground ffffff
background 0639a1

gfxmenu /boot/grub/message

title SimplyMEPIS Linux at hda2, kernel 2.6.15-26-386
root (hd0,1)
kernel /boot/vmlinuz-2.6.15-26-386 root=/dev/hda2 nomce quiet vga=791
boot

title Microsoft Windows XP Professional at hdb1
rootnoverify (hd1,0)
chainloader +1

title MEMTEST
kernel /boot/memtest86+.bin

Does anybody see anything wrong and can anyone help me?

{Note : My friend brought up the GRUB menu commands and put them in Kwrite , so I have no idea how he get there or how to edit it}

First, what's the problem? Is it that windows doesn't boot with this config?

If so, change this:
title Microsoft Windows XP Professional at hdb1
rootnoverify (hd1,0)
chainloader +1

to this:
title Microsoft Windows XP Professional at hdb1
rootnoverify (hd1,0)
map (hd1,0) (hd0,0)
map (hd0,0) (hd1,0)
makeactive
chainloader +1

windoze wants to be on the first partition of the first drive. it generally refuses to boot unless you tell it a little lie (the map lines).

As for editing /boot/grub/menu.lst, it can be edited by root. So if you are logged in as user, su to root, and use a text editor such as vim or emacs to edit. If you want to use a GUI editor as root, do this:
as user, give the command 'xhost +localhost'.
su to root
start the editor from command line: example: /opt/kde3/bin/kwrite /boot/grub/menu.lst (that's where kwrite executable is in SuSE 9.3. get the location on your system with 'which kwrite').

This is one of the biggest problems that can happen to new users. My advice: don't let your friend do stuff on your computer unless you know what he is doing. Make him show you...

The grub config files are in /boot/grub the name is menu.lst or grub.conf
The easy way to edit a config file is to first issue "su" to become root, and then use a SIMPLE cli editor like nano.