Grub.?

[James Elliott]

After installing Ubuntu on my PC I get the GRUB boot manager which allows me 
to choose between Ubuntu and Windows XP.

For the time being I still need Windows for my work.  Ubuntu is the default 
in GRUB so I need to select Windows when booting up to do work related 
computing.  However, If I am distracted by anything, the computer default 
boots into Ubuntu and then I have to shut down Ubuntu and start all over 
again.  This happens a bit too often and is a little frustrating.

I have looked on the Internet (Google) which says to edit 
/grub/boot/menu.lst but I cannot find a way to do that - in fact, I can't 
find the file?

I would be obliged if someone could help me modify Grub.

Many thanks,  James