As a side note.
When you want to add for an example a testing tool later on and you don't know what to put it under.
Put it under Linux OS/ other Grub4dos campatible ISO. That usually works just fine.
In your case you will need to choose windows vista / 7/ 8... etc.
But if you want to add a testing tool like Ultimate boot. (a very nice package of tools) you should choose Linux OS/ other Grub4dos campatible ISO. (That is if you are lost on where to put it)