Generally I would only use Not when dealing with boolean values. Ie, values which are true or false.
Ie:
If Not GameOver
Where gameover can equal true or false.
In your examples, I would avoid using not. I would do this instead:
If Soundflag <> 1
Ie:
If Not GameOver
Where gameover can equal true or false.
In your examples, I would avoid using not. I would do this instead:
If Soundflag <> 1