perhaps some games use "catalyst control centre", if that crashes the game does not run?
it is possible this "catalyst control centre" does not support x64 systems. when I decided to go with x64 instead of x86, I was repeatedly assured that everything that runs on 32 bit OS will continue working in a 64 bit system. I quickly found that is not the case nearly 60% of the time. Many of my games refuse to run on my 64 bit system, claiming its an OS not supported, too little memory, hardware not compatible, etc, others just flat out tell me they do not work with a 64 bit OS. many of my games, I cannot play. others I had to get new software (luckily I was able to many of them via torrents so the cost was not too much).