Client doesnt open...

Hello all..

I got a "custom" AutoPatcher.
now when some people download and use it.. they get error:

CAnt start up client.

send / dont send..


I have let m done this:
-OPen game with CrankCo.exe(autopatcher)
-download .net 4.0
-download sp2(xp)


any 1 has an idea why/what causes the error?

How do u send the .exe after?