consuming ws

Hi all ,

I am consuming ws which works great on my deploying machine but on customer p.c I am getting the error : .Net engine can not be start

my machine is window server 2008 64 bit , the client is Win7 64 bit ( it works on most client's machines  , 32/64 bit most of them are win7/8)

I have checked that recent work frame is installed .

What can be the problem ?

using 12.5.1 build 4015

Thanks

Moshe