1st. : Open "C:\WINDOWS\Syswow64\odbcad32.exe" ; select "SystemDNS" and remove all dns's.
2nd. : Add the new dns's that the ODBC connection is needed as follow :
"Add" -> as new data source you select "SQL Server" -> click "Finish"
"Name - the name of DNS (ex. MuOnline, MuOnlineJoinDB,....)" -> "Server - the name of the PC where is installed the SQL Server, or leave it as "localhost"" -> click "Next" ; the next step leave all the settings as default -> click "Next" ; on the next step in the top of the window select "change the default database to : "and select the database MuOnline"" ->"Next" and "Finish"
Do the same thing to the others ODBC connections registered in the .reg file.