can i install vista basic with home premium reg key?

i have an upgrade dvd that came with the older acer laptop i had.(which had vista basic)
can i install vista basic into my current hp laptop with that? (over the premium version that i dont want which is what the hp came with?)
please dont ask why i want to do this as there are already more than one thread about my reasons
or will there be some sort of legal issue with that (it shouldnt be though cause i am downgrading and not passing my premium onto anyone else) but im just wondering if there will ever be any issue if i go online with it.
would i have to use my older acer reg key? (im assuming this might give me a problem if i ever go online?)
or the ome premium key (which might not work cause ill be trying to install basic and it is a premium key)
can i instal vista basic with a home premium reg key?

 

yea.... it wont work...... what you can try is calling microsoft and asking thwem if you can trade them cd keys, but i bet they will say no

 

Nope you cannot do that. If you really want vista basic you can buy a license.