I had an issue recently where I was not able to remove an instance of SQl Server, or so I thought. I kept on trying to remove the instance via Microsoft SQL Server 2014 RATHER THAN Microsoft SQL Server 2014 (64-bit). Once I selected the 64 bit option in Add-Remove Features I was able to finally gett rid of the instance I didn't want! Pretty dumb of me to not see the 64 bit option right away but there you go, sometimes you can't see the forest for the trees.