Using loStreamReader As New StreamReader(lcFile, System.Text.Encoding.Default) cString = loStreamReader.ReadToEnd() End UsingIn our daily operations, we process about 4000 zip files, where each of them contains about 30 or more files, where I have to get the file type of each. So, basically, this method is called about 120000 times on a daily basis. I see this is, of course, impacted by the size of the file. So, if the file is bigger, it will take more time to do the above.