Running rake task from Windows scheduler

Question

Hi, I have a custom Rake file, which I want to run periodically(every day). I am using a Windows machine, and have a .bat file, which basically does

cd path/to/applicaion
rake filename 

I am using the windows scheduler to run the bat file but it aborts, complaining that some gems are missing. However, when I start up a command prompt(using InstantRails.exe), and then run the .bat file from there, it works as expected. I think there is some issue with the PATH, but I am not able to figure out what exactly needs to be done?

Thanks!