That's an ugly way of doing things...
You have a choice of using either the Windows Bootloader or Grub.
I have gone both ways in various installations over the years, and since I am primarily a Linux guy now, I prefer using Grub, if only because installing new Linux distributions is easier once the inital setup is done.
First, you want to back up all of your data. Put it in a safe place, on a separate storage device. If you have the time and resources, I'd recommend making two backups, one to a remote drive and the other to optical media such as DVD-R.
You will want to have a WIndows Recovery disc available to use that is compatible with your current Windows Operating System.
If you decide to use the Grub 2 bootloader, then installation deviates from the advice on your link this way-- let the installer put the boot menu on /dev/sda. This will break your Windows boot, but to fix that, you will want to boot up your recovery disc, go to terminal and enter the following two commands in order:
That should fix your Windows install, and any time you reinstall a Linux package, the new package will install is Grub over the existing one, detect all your Operating Systems and everything will be hunky-dory.
If you prefer to use the WIndows Bootloader instead, there is a way to do that, as well... I seem to have last done this in 2005, so the methods may be entirely different now, and my way requires patience and a degree of comfort with command-lines, but here's a record of my attempt using Win XP and Slackware: http://www.devhardware.com/forums/opera ... 66256.html