Could Not find or load main class

[Agunbiade Ademola]

I had been on study on Java for the past 3 Month and been to the use of TextPad IDE and Tomcat i don't know how i mistakenly make my Application unable to detect my VM so when i compile my App it compile well but when i run it it prompt this is error: Error: Could Not find or load main class DEMO1
Press any key to continue.

kindly help me out on how initial Path of Window 8 suppose to be because i thought this might be the cause and id any other remedy help me out.
I'm using Window 8. Please help me out.

[Steve Luke]

This isn't a windows problem or a problem finding a VM. This is because your classpath does not include your main class (the class you are trying to run). If you don't know how to use the IDE to run the app correctly, stop using it and open up a command prompt and use these directions as a guide on how to run your application.