Appian agent not running after getting download agent on windows machine

Hi,

      i am new to Appian. I am not able to find out why Appian agent ( AppianRPAagent.exe ) is not running in my windows machine. I just downloaded the agent i my system, I am using windows 7,  RAM 8 GB . But when i double click on the exe file it is not executing. What may be the cause?