Ubuntu Answers

If you did a clean install on your hard drive and installed Ubuntu before you installed Windows, then Ubuntu will not have anything in the grub configuration for Windows. This is where you’ll have to do a bit of manual editing to the grub boot menu file.

Open the file /boot/grub/menu.lst with the following command in the terminal:
sudo gedit /boot/grub/menu.lst
Copy this code and insert it at the bottom of this open document (In the windows portion you can call windows whatever you like):
title Windows 95/98/NT/2000
root (hd0,0)
makeactive
chainloader +1

Look at the top of this document where it annotates that the grub loader is hidden by default. If you want the selection to be visible instead of having to hit (esc) when booting place a (#) sign in front of this line.

Save this document and reboot your system

Note: You should also verify that hd0,0 is the correct location for Windows. If you had installed Windows on the 4th partition on the drive, then you should change it to (hd0,3)