Ok, now some people may prefer to have 2 Operating systems on their hard disks. This may be because some software isnt compatible with one and is with the other.

I am going to use Windows XP in this example

So, how do you do this?

Well there are 2 ways

1) You can edit the boot.ini file. You can access this by going to Start >>> Run and typing msconfig and then clicking on the boot.ini tab

2) Your original file looks like this:

3) You then add this: (im going to use the Home Edition to modify the file)

multi(0)disk(0)rdisk(0)partition(2)\WINDOWS="Micro soft Windows XP Home" /fastdetect

4) Your boot.ini file should look something like the one as shown below:

There is also another way, (You will need your Windows XP CD to do this, or 6 bootable floppies)

1.Boot with XP CD or 6 floppy boot disk set.
2.Press R to load the Recovery Console.
3.Type bootcfg.

After doing this, you should then have a boot menu, allowing you to select your preferred Operating System.