How to Clean install Windows (Upgrade) Versions
Posted on 04. Dec, 2008 by Mike Halsey in guides and how to's
Microsoft have for years shipped upgrade versions of Windows. These were cheaper versions for people who owned a previous copy of Windows. There was a known bug with Windows XP, that they fixed in 2007 with the final distributions of XP install CDs, that when the installer asked to see a CD containing a previous copy of Windows, you could simply get it to look at itself in the drive and it would continue happily.
With Windows Vista and later however they removed this but this presented a problem. If you need to do a clean install of Windows, how can you do it from a upgrade disc?
One way is to first install a copy of XP and install Vista over the top. Microsoft may change this with Windows 7 but I’ll update this article when we know. This isn’t the best way however as it will leave behind some files from the earlier copy of Windows that could perhaps slow your computer down or cause problems.
A better way would be to install the operating system on top of itself to upgrade it. How can you do this?
In the image above (click the image to view it full-size) you can see that the WIndows installer now allows you to install it in evaluation mode, which will allow you to use a copy of Windows without having to enter a product key for up to 30 days. The first time you install Windows from a formatted drive you should NOT enter your product key and instead untick the box labelled Automatically Activate Windows When I’m online.
Windows will then ask if you really want to install it without using a product key, jusy click No at this point.
Windows will now ask what version of Windows you want to install. You should make sure that the version you select is the SAME as the version you intend to use otherwise the upgrade process later may not work. Tick the box I have selected the edition of Windows that I purchased and click Next.
You now need to work through the installation process as normal. When you are presented by the desktop and before installing any software or updates run the installer on your Windows DVD. For the reason for this refer to my Upgrade or Clean Install? article.
Work through the installer and enter your product key when prompted but when presented with the choice of performing an upgrade or a clean install choose Upgrade as seen in the image above. This can take up to an hour and half to do, so if you need to do the housework, this would be a good time. Windows will happily install over itself though and you will end up with a fully working copy of Windows.
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