Is there any way I can use HTML5 and JavaScript to modify a file on my system? I\'m OK with running Chrome or Firefox with specific options or opening permissions i
No, as this would be a security vulnerability. As pointed out there are sandboxed file systems, or local database storage in HTML5, but not access to the whole file system.
You could achieve it with a certified Java applet, if you really wanted to achieve it through the browser. To be honest the browser is not the best place to be trying such things.
Yes, you can do this, this link details some of the available functionality:
http://www.html5rocks.com/en/tutorials/file/filesystem/
Just remember, it's not supported in the major browsers yet, and it's likely when it is many of your visitors will not upgrade for quite some time.
VBScript should be appropriate in your case. You will have to lower your internet zone security level though.
Once it's done just use ActiveXObject("Scripting.FileSystemObject")
and its MoveFile method.