After effects cs4 don't launch

Hi everyone,

I have an issue i've never seen before.

I launch after effects cs4, i have the loading round near the cursor for 2 seconds, then nothing. No splash screen, not even in the application bar.
Just in the process tab at 72Mo Ram

Im running the cs4 32bits on 7 64b
i have 2 xeons E5-2650 proc and a firePro v7900

CS6 is working but i want CS4.

if you have an idea...