APP CLOSES WITH NO EXPLANATION =

Caused by;

A, Incompatible hardware (usually video card or not enough memory).

Solution; 

None, your pc is crap (try upgrading drivers). 

B, Licence issue.

Solution;

1. Try the steps in the ADOBE LICENCE RECOVERY TOOL.

2. If that fails go to the CS4 LICENCE RECOVERY folder (LICENCE METHOD 1) and 
   follow the instructions there.

3. If that fails go to the CLEAN INSTALL folder and follow the steps 
   there.