unity and MSSQL connection.. socket exception

try to connect with mssql but there are some problems.

I copied System.Data.dll files and I18N.CJK.dll files from C:\Program Files (x86)\Unity\Editor\Data\Mono\lib\mono\unity into my project's Asset/Plugins folder. Also I did some settings for port 1433 in Firewall and SQL Server Configuration.

But the problem wasn't solved. First, when I build my project, there's an error saying 'System.ComponentModel.Component' isn't defined #$!@$# in System, Version 2.0.5.0. %!@% about the code " SqlConnection cnn = new SqlConnection(); ". So, I additionally copied System.dll files from (Is it Okay?? I'm not sure) C:\Program Files (x86)\Unity\Editor\Data\Mono\lib\mono\unity into my project's Asset/Plugins folder, then the build was succeessful.

However when I play my game in unity, it says socket excepton : An existing connection was forcibly closed by the remote host.

I think I did all the things people say but it still doesn't work.

I use Window 8 64bit, mssql 2014 express, and unity 4.5.2f1 ver. Is there any problem with that? Or what should I do ?? I've suffered from the problem for 3 days.