The process cannot access the file 'D:\Inetpub\wwwroot\unsd\mdg\_Export\MDG_Export_20140902_074925192.zip' because it is being used by another process.
   at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
   at System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy)
   at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options)
   at System.IO.File.Create(String path)
   at Unsd.Mi.Web.Handlers.ExportHandler.Zip(String zipFileName, String fileName, String content) in d:\Inetpub\wwwroot\unsd\mdg\Handlers\ExportHandler.ashx:line 107
   at Unsd.Mi.Web.Handlers.ExportHandler.WriteOutputFile(String content) in d:\Inetpub\wwwroot\unsd\mdg\Handlers\ExportHandler.ashx:line 138
   at Unsd.Mi.Web.Handlers.ExportHandler.ProcessRequest(HttpContext context) in d:\Inetpub\wwwroot\unsd\mdg\Handlers\ExportHandler.ashx:line 176