Windows 7: I lost my Vista box and disc, can I still use upgrade?

I have a valid legal copy of Vista Home Basic installed on my computer. I have lost the install disc and box. I would like to do a clean install of 7 home premium on a new empty HD (a different HD than the Vista install) on the same computer. Is this possible with the upgrade version?

as long as you have a valid key yes Clean Install with a Upgrade Windows 7 Version

by valid key do you mean the Product ID that is displayed in Computer...Properties ?

A little clarification, as long as you have a legal activated copy up and
running on the computer, yes I do believe you can install to a different
Drive or partition. Before you install though, there are programs out
there that you can run to retrieve your install key. But for the life of me
I can't think of the name right now.
I'm sure someone here will supply it.
Edit.
I remember now http://www.magicaljellybean.com/
This should do the trick.

Use jellybean key finder.

Ken

Told you.
Write that key down and store it somewhere safe.
You may need it again someday .

Here is another Keyfinder. If you make your new installation, I suggest you disconnect the drive with your current OS. That way you do not run into a double boot situation which will give you some grief with the MBR the day you want to uninstall the current OS. The uninstall you will have to do because you cannot use the key on 2 versions of the OS.

As suggested, unplug the Vista HD before installing Windows 7, then afterward you can replug Vista back in if you want to dual boot it, set Windows 7 as first HD to boot (after DVD drive) in BIOS boot order, or trigger Vista using the F-key given on first bootup screen for one-time boot menu.

However, while this is the cleanest way to dual boot with two HD's, you'll need to do a Repair Install (upgrade over itself) to get Windows 7 to accept Upgrade Version key since it won't see Vista when you boot the DVD and will reject the Upgrade key at first.

If you choose to let Windows configure the Dual Boot by keeping Vista plugged in during install, you won't have to do the repair install, but it will be harder to remove the Vista HD later, requiring marking Windows 7 active and running Startup Repair up to 3 separate times from the booted DVD or Repair CD.

thanks everyone