Web Forms :: Creating Files From MIME Content?

I am using the below code to create file after reading the body

from the database. body contains the content of the document in MIME format.

string dataDir = "D:\Temp_Attachment\";
string strXml = System.Text.Encoding.UTF8.GetString(System.Convert.FromBase64String(body));
Stream wordFile =
new
FileStream(Path.Combine(dataDir, filename),
FileMode.Create);
StreamWriter xmlWriter =
new
StreamWriter(wordFile,
Encoding.Default);
xmlWriter.Write(strXml);
xmlWriter.Close();
wordFile.Close();

The problem i'm facing is that above code works for text files.

When I'm creating image files or pdf files, those files give an error on opening.