Driver Installation

I am having dificulty installing the Arduino MEGA 2560 driver. I have turned off the requirement for a digital signature requirement but when the driver installs I get the error message,

"Windows found driver software for your device but encountered an error while attempting to install it.
Arduino Mega 2560
This device cannot start. (Code 10)"

I have tried with various computers and operating systems and always have the same issue. I have also tried with various USB cables, again with the same issue. I am currently trying on one machine with XP and another with windows 8. Any advice would be welcome! Thanks in advance.

I would re-download the Arduino IDE system, and perhaps install it in another folder than the original. MAYBE the driver you have is corrupted somehow.

Thanks for the advice,
I've tried redownloading into another folder and had the same error message. I also tried the same thing with an older version of the software and still no success...

Wow.. That is weird...
Almost only remaining?? - bad Arduino? - Clone Arduino with wrong USB internal data?

Sorry, I'm not sure what you mean by, "Almost only remaining?? - bad Arduino?"
Could you explain how to Clone Arduino with the wrong USB internal data? Is this a possible solution?