Ok, lets do a test.
Go to the FSBuild Aircraft folder and copy all the files to a backup folder.
Delete the files from the Aircraft folder so it is enpty (except for the Library folder).
Make a backup copy of the fsb_aircraft.cfg file.
Edit the fsb_aircraft.cfg so it is empty and save it.
Go here:
http://www.fsbuild.com/aircraft_performance.htmlDownload the Embraer 170-100 to a temporary folder.
This is different (author) from your post in this forum.
Read and follow the instructions.
Now we have only one aircraft to deal with for the test.
Start FSBuild
Select the E170 (Options, Settings, Default Aircraft)
Save the configuration (save config options).
Exit FSBuild
Start FSBuild
Does it show up?