You have the tool on your CD. Boot it (and let it take its usual 5 minutes to detect hardware and load drivers for stuff you'll never have - sorry, pet peeve - could have a live-cd booted, configured and surfing the net in less time). When you get to the "install" screen, you'll see an option to hit "r" to go to recovery console. Hit it. You'll get a DOS-like prompt. Type
and reboot. You should boot into Windows (yes, Linux in not accessable at the moment). If so, its pretty easy to reinstall lilo or grub from there (we can show you if necessary).
NOW BEFORE YOU DO THIS......................
First look into your bootloader config and see how you're booting Windows. Under your menu.lst (grub), in your "Windows" stanza, do you have the line "chainloader +1"? What does your /etc/lilo.conf file have in it regard to Windows? One line (or word) may fix it all.