so after not looking at this for a while I am back to trying to get it to work. I didn't notice this last time but when trying to install I noticed that the data directories page is pointing to C:\Program Files (x86)\Microsoft SQL Server\MSSQL12.TRELVSQL02\MSSQL\DATA. But the instance of SQL Server is installed in C:\Program Files\Microsoft SQL Server\MSSQL12.TRELVSQL02\MSSQL\DATA.
I am wondering if this is why I was getting the "instance already in use" error. Perhaps because it was installing it to a different directory but with the same instance name. The problem is if I change the install directory to C:\Program Files\Microsoft SQL Server\MSSQL12.TRELVSQL02\MSSQL\DATA I get an error that says the file already exists.