Injctor trouble. Please help!

Alright, I just downloaded the PerX injector
but when i put the stuff in it and run Combat Arms,
it just shuts Combat Arms down. Please tell me what
i am doing wrong!
ALSO. I dont understand how and what people mean by changing Combat Arms' "Compatability."

For the PerX Problem trying runnin It as admin Then try running both CA+PerX as admin

And

For the compatibility answer Uhh,right click on your CA launcher go all the way down to Properties then go to compatibility then there should be A scroll down box with a list of compatibles click on one then hit apply+OK

Thank me if i helped

Heres a screenshot to help you even more