Geez guys calm down and DR EVIL got nothing useful to post don't post anything.
Serge was being helpful though MCiN7 as "Digital River Files" are possibly who he has downloaded his TDU from but seeing as he says the "disc" I'm guessing he has a physical disc version.
The fact he mentions a cracked exe though leads me to ask though have you actually bought your copy because if not then no help will be given here. However if you've bought your own copy; ie it's not a friends in other words then all we can suggest to you is:
Key question first
1) Where did you get your game and Megapack from?
Then
* Remove any DAEMON tools you may be running
* DO NOT use altered or edited exe's for the game
* Install the game first and try running it and hopefully you should be prompted to update
* If prompted then close TDU and goto http://www.testdriveunlimited.com and follow the link to Download the Patch
* Run the patch (make sure to do this while the game is closed)
* Run the game and check for 1.66 showing in the main menu
* Install Megapack and note the Activation Key is not your TDU game serial, it is the Multiplayer Key you would have been sent when you purchased the Megapack, again if you have acquired the Megapack through other means then we cannot help you
If this still doesn't work, post more info about your System Specs and such or even try the EU Forums where the community is usually quite good about solving users issues!
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And MCiN7 don't start getting all heated and angry due to some members, report them or ignore them and help the OP yourself. And also mind your language, censoring your own words and using asterisks is not permitted.