Staffjudging by the (error) out put message, it does not seem to me that you are providing the right command line arguments. By all means, if you have TestComplete.exe set as an environment variable, the command line args that you provided should work. However, judging by the message, you are doing something like:
TestComplete.exe TestComplete.exe "C:\fullpath_to_your_pjs_file" /some /other /switchesConcretely, it seems to me that you are calling on the executable twice. (apart from the fact that the executable itself doesn't seem to be capitalized in the format that i expect (but i am not sure if this has an affect on the validness of the executable file itself)