'sh.exe": ionic: command not found on windows 8

I am at the end of ionic app development & about to finish my first ionic based mobile app. I have my app developed in cordova with ionic framework & angularJS. Through git bash when i entered following command after long time of Idle work i got the above error.

Command

ionic build android

Here it is showing me the above error that i haven't even seen before when i was developing app & building it for testing. Thing is after one month of non working phase on ionic application, when today i opened Git Bash & tried building APK after long time then it is showing me the error what could possibly happened here?

You do not have ionic installed, or you do not have it in your search path. Add the directory of ionic to the PATH variable to fix it.

Well i got it. I have not updated the ionic version after long time of non working phase. When i updated the version it built my app.