I've decided to install Windows 10 on my Acer Aspire E15, and I did it today, and I notice great difference in terms of performance over Windows 8.1. (I will point out what I did to make a clean installation on my Acer Aspire Notebook 1. Activation. It will took 24-48 hours to activate if you make a clean installation. So, upgrading from your previous version is recommended. There are lots of complaints on various forum saying they could not activate windows after clean installation. Microsoft also mentioned that you need to upgrade first before make a clean installation. However recently I found that after the installation, you need to log in to your Microsoft account (live account) and it will activated within 1 or 2 days. 2. Windows Version Check your windows version so that you can upgrade for free, for example I am using Windows 8.1 Single Language so I can only install Windows 10 Home. If you install Windows 10 Pro Over Windows 8 (basic edition) you will need to purchase the