Disable opening browser from Windows Explorer Address Bar
You can't turn it off.
But you can enter command prompt by pressing Win+r and typing cmd.
There it doesn't open a website if you type it, just an error message.
The only settings I can find will disable "Searching", but still open up Internet Explorer with a site that says the URL cannot be found :-/
Instead, Hold Shift on your keyboard and Right Click in the directory you wish to Open the command prompt from: Select "Open Command Window Here" from the Context menu... This works in Windows 7.