I have uploaded limesurvey206plus-build150831and installed all the pre-requisites.
When I first open the site it only gives me the option of a MySQL server install in the drop-down.
How do I choose SQL Server?
Is there is guide on installing LimeSurvey to SQL Server backend?
I am not an expert, but if the installation routine only gives you the option to install on MySQL, it is probably because your webserver installation is lacking the necessary connectors to other databases.