I have just purchased an Acer Iconia tablet in the sales. It is to replace my Nexus which died a computer death in January last year. Nice machine, but it is pre-loaded with Windows 10. Everything defaults to Windows or Microsoft and none of their resident programs can be removed without a master administrators password (which I do not have access to).
I have installed Firefox as my preferred browser and that is OK. I tried to install Thunderbird as my E-mail reader, but the system would not activate the on screen keypad to set up the software, I had to import a keypad app. The e-mail default is Microsoft mail, which is running in the background - I could not get Thunderbird to engage with my E-mail server. In the end, I set up Microsoft live mail- which took me all of 2 minutes to sort all of my different e-mail identities.
I am not over impressed with Windows 10. How I long for Android Lollipop!