Windows 7: Vista Business to Win 7 Home Premium Upgrade

I am currently using Vista Business and want to install Windows 7 Home Premium.
Upgrade Advisor does not show Home Premium as an upgrade but I don't need anything more than that and don't want to pay the full price for what is basically a downgrade.

It doesn't make sense that I would have to pay for a full version of Home Premium when I already have a Vista Business version.

Does anyone have an answer to this problem.

Thanks,
Charlie

Hi Charlie
Look on this thread and this post
If you have a Vista License, you are entitled to using an Upgrade version of Windows 7. Yuo will have to do a clean install, you are not allowed to do an in-place upgrade from Business to Home Premium (unless you want to tweak your installation files or your registry, which I don't recommend, a clean istall is a better way to go anyway)

Let me know if you need additional info