I'm having a hard time understanding what you have tried to deal with the error you were getting. All servers have file permissions, Windows or Linux, it does not matter. Xamp is an automatic server setup that uses Apach, MySQL, and PHP, the amp part of the name is an acronym for this.
The sql template that it referring to is not a page template in the templates directory, but it is a db.sql file that is in the install > scripts folder. What is the exact error that you are getting now when you try to run through the installer? It might be a good idea to start the process over again from scratch if there is anything strange happening. If you start it over make sure to delete any existing files and tables from the db so it uses a fresh set of files and information.
