The CD/DVD it is asking for is the "Anytime Upgrade" disc. Most windows
Vista version DVDs are "Anytime Upgrade", meaning they have the entire OS,
but only the parts of it which belong in your version are "activated".
Theoretically you can "Anytime Upgrade" and only have to download a key code,
the isntall would work from your original disc. In many cases like yours
(and mine) you need to actually buy an "Anytime Upgrade" disc.

I don't know about your country situation. Hope this helps.