For anyone who’s interested, I’ve just managed to get my spare Mac Mini dual booting Windows 10 and OS X. The Mac was purchased a while back on eBay for £99*, I upgraded it with an SSD and 8GB RAM and kept it as a backup for my iMac should anything go wrong.

In my junk cupboard I had rediscovered a Dell Inspiron that was beyond economical repair and lying in bits for scrap. But it has a Windows 7 Pro COA stuck to the bottom… perhaps not so worthless after all?


To install Windows 10 using a Dell Windows 7 Serial Key

Preparation: Download the Windows 7 Pro ISO from Microsoft and use Disk Utility to make a DVD. Partition off some of the Mac Mini’s SSD to use for installing Windows 7 and format as MSDOS, also using Disk Utility.

Installing Windows 7: Insert the Windows 7 Pro DVD and reboot with the Alt key down to select it as the Boot Disk. From that point just follow the prompts to install Windows. Once finished it needs to be updated as far as possible, certainly to SP1.

Activation: Now try to Activate Windows using the Key on the Dell COA –it will likely fail to do so over the Internet so, (as advised by the screen dialog) call the automated telephone system –if that fails (it did for me) call Microsoft Support on the free-phone number. I did so and read out the Installation ID to the operator as requested – she then gave me the Response Code which I entered and Windows was Activated. Woohoo!

Upgrading to Windows 10: Now go to and start your free upgrade. You probably have until September 2016 so no hurry but my whole reason for doing this was to get familiar with the new Microsoft OS. So far I think it works pretty well…for Windows! It’s a good idea at this point to download a copy of Belarc Advisor which can extract the Windows 10 install Key–keep this in case you need to reinstall from bare metal in future.

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*Postscript: The early 2009 Mac Mini was an absolute bargain and a cracking little computer for this purpose, very reliable, very low power consumption, full featured and fast with an SSD. There are loads on ebay, not all going for £99 but still great value and they will run El Capitan the latest OS X.

  • Mac mini (Early 2009)
  • Processor: 2.26 GHz Intel Core 2 Duo
  • Graphics: NVIDIA GeForce 9400 256 MB