[modeller_usage] error in running mod9.19

["Saman Yousuf Ali" <saman.ali AT iccs.edu>]

I have recently installed modeller 9.19 in my windows system with python
3.63 (64-bit). It was running perfectly fine. Even yesterday,I run basic
modelling tutorial but now when I run command mod9.19 build_profile.py It
gives me following error;
'md9.19' is not recognized as an internal and external command, operable
program or batch file.
Kindly help me to fix this issue.

Regards
Saman