if (window.ActiveXObject) {
        try {
            var fso = new ActiveXObject("Scripting.FileSystemObject"); 
            fso.CopyFile("C:\\Program Files\\GM4IE\\scripts\\source.txt","C:\\Program Files\\GM4IE\\scripts\\target.txt", 1);
            fso = null;
            }
            catch (e) {
            alert (e.message);
            }
    }
I am getting error : 
"Automation server can not create object" on the line where I am creating ActiveXObject instance.
I understand that it's considered very bad to access hard-drive data using javascript but I just need it.
I am using IE8 , Greasemonkey4IE  to run my javascript.
Thank you,
Mohit
******************************
    function WriteFile()
    {
       var fso  = new ActiveXObject("Scripting.FileSystemObject");
       fso.CopyFile("C:\\source.txt","C:\\target.txt", 1);
    }
I've put the above code inside a simple HTML page and it worked perfect.
http://www.c-point.com/JavaScript/articles/file_access_with_JavaScript.htm
You can find the similar code on above mentioned location.
I modified it a bit, tough.
But when I am trying to run it through GreaseMonkey4IE it simply spitting the same error I specified earlier.
I did it guys, but thanks a lot for your quick and helpful replies.
All I did is : 
    Go to Tools > Internet options > Security > Custom Level
    Under the ActiveX controls and plug-ins, select Enable for Initializing and Script    ActiveX controls not marked as safe.
 
     
     
    