how to upload word document and show it in c#

You can store file either in BLOB format or in directory, to show word document in ASP.NET you need to use Response object
see below snippet

//store file in DB
public static void databaseFilePut(string varFilePath) {
    byte[] file;
    using (var stream = new FileStream(varFilePath, FileMode.Open, FileAccess.Read)) {
        using (var reader = new BinaryReader(stream)) {
            file = reader.ReadBytes((int) stream.Length);       
        }          
    }
    using (var varConnection = Locale.sqlConnectOneTime(Locale.sqlDataConnectionDetails))
    using (var sqlWrite = new SqlCommand("INSERT INTO TABLE1(COL1) Values(@File)", varConnection)) {
        sqlWrite.Parameters.Add("@File", SqlDbType.VarBinary, file.Length).Value = file;
        sqlWrite.ExecuteNonQuery();
    }
}

Here the column datatype should be VARBINARY(MAX)
IFRAME is a nice control to show word file in browser, Or if you don't want your file to get edit you can save it as HTML and the show it