http://forums.technicpack.net/index.php/topic,4191.0.html
"Opening the .exe does nothing, or flashes a loading icon, or says "checking launcher version", then closes.
This is a Java issue. The most common cause is using 32 bit Java. If your Operating system is 64 bit,
make sure you update to the latest 64 bit version of Java. Links on www.technicpack.net.
If your Operating System is 32 bit, you will most likely have to just use the .jar version until another
solution is available. Go to .techniclauncher and there should be a .jar in there. If not then download
it from www.technicpack.net. Read further up the list for how to determine the bit version of your OS or JAVA."