This is a bit complicated it seems.
I own Windows Vista Ultimate 64-bit (Retail). It was okay, but around a couple of weeks ago I had some system crash and at that time I decided that I will install Windows 8 as soon as it comes out.
However, because of some problems in Vista, at the time of crash, I installed Windows 7 trial. I had some urgent work to do which I accomplished and then I switched the PC off.
Now I have purchased Windows 8 Pro Upgrade ($40 version). If I go for a clean install, will it be able to install Windows 8 on not-activated Windows 7? During activation, if it asks for Vista serial number, I can provide it.
Or will I first have to install Vista and then only it will allow me to install Windows 8?
Also, I used the Upgrade Assistant to download Windows 8 on my laptop (Windows 7 OEM). Will it work on my above mentioned desktop?