Windows 7: Upgrade HP to Pro using same Vista installation

Hi folks...
I was running Vista HP and planned to upgrade to Windows 7 Pro before I realized it would require reinstalling programs. So I called Microsoft and cancelled the Windows 7 Pro order and purchased Windows 7 Home Premium Upgrade locally. But I'm having problems running all Call of Duty games with hard crashes.
Meanwhile, Windows 7 Pro Upgrade arrived in the mail despite my having cancelled it and I found that indeed, Microsoft billed my credit card. Now, I've a mind to install Windows 7 Pro on my desktop and just do the resinstalls, and then use the copy of Home Premium Upgrade on my laptop. I'm sure I'll have no problem running COD in virtual XP mode on Windows 7 Pro.
So, a couple questions:
- To install Windows 7 Pro, I assume I have to first install my earlier version of Vista? Can I do that if it's already "linked - if that's the correct word" with the Windows 7 Home Premium upgrade I've had in place for a couple of weeks and is registered?
- Can I then install the Windows 7 Home Premium upgrade on my Vista HP laptop, despite that it has already been registered on the desktop? Or do I need to call Microsoft?
(I hope this makes sense.)

Hi,

No, you don't need to reinstall Vista. Pro will be quite happy to see HP you have installed as good enough to qualify.


You should be able to use the HP on a different machine - it might activate ok ( they sometimes do )- much more likely you will have to call - as it is now on a different machine.

Great. Thanks!
I'll back up to new D drive and assume Windows 7 Pro will wipe the C drive where Windows 7 HP currently resides. I believe it gives you a choice of which drive to install on.

Yes, it gives you a choice.

Windows 7 will not "wipe the drive" itself. If you want a clean formatted HDD, you need to boot from the installer, select Custom>Advanced tools and delete existing partition(s), create New one(s) and Format before install.

Drive Options ( advanced). Highlight a partition you want to "clean" and click Format. You only need to delete and recreate if you want to change the sizes/layout.

Is it a cleaner install to delete the partition (contents) first then make a new one to format?

Or is it only going to matter to format and can't get any cleaner than that unless you zero it, which many say is overkill?

Doesn't make any diff. Greg - Format is just a Quick format - clears the log files.

Delete just removes from partition table. All the data is still on the drive - and recoverable.

Windows can't the "see" the data and carries on as if it isn't there.

You can use a special app to wipe it - only if you are going to dump the HD , or sell the pc - to remove anything sensitive.

I used GWScan to zero all my drives for a long time, until I got convinced it is overkill.
Just seemed cleaner.

Hard work for the drive.