ADO.NET Failed to load msxmlsql.dll

How to fix this error?

System.Data.SqlClient.SqlException: Failed to load msxmlsql.dll.
at System.Data.SqlClient.SqlCommand.ExecuteReader(Com mandBehavior
cmdBehavior, RunBehavior runBehavior, Boolean returnStream)
at System.Data.SqlClient.SqlCommand.ExecuteNonQuery()

am i missing something that needs to be installed on sql server? is this a
client side ado.net issue?