There are about 40 threads about this exact same thing. Try using that search bar in the top left corner. Also, I checked, he isn't a hacker.
EDIT: @warpspeed, he means he owns the game.
One solution that has worked in the past is to download the .jar file from http://www.technicpack.net/download/ (pick the third from the left (Linux/Jar)). If you are using Internet Explorer you will also need to change the file extension (the ending of the file) to .jar instead of .zip. Once you’ve done that, all you need to do is double-click on the file to run the launcher.
wow! Thanks for all of that helpful info. You aren't going to get any help unless you actually take the time to find out all that info. Read the sticky, it tells you where to find all of that info.
Double check your Java version (make sure the bits match up) that is the biggest issue.
Serious for a second though... Why did you pick this forum to ask and not the Xbox forums?