REGEX para eliminar comentarios

[rubencho]

Hola...estoy tratando de eliminar los comentarios de un codigo de aproximadamente 45000 lineas...pero solo quiero eliminar los que para mi son validos...tengo un ejemplo de lo que se podrìa o no eliminar.....alguein me puede echar una mano con la expresion regular?

line xxx1 with valid code (don´t erase)
line xxx2 whit valid code (don´t erase)
line with valid code plus valid comment //this is a valid comment
line with valid code, plus spaces at begin plus valid comment //valid comment
line with tabs at beginning and valid comment //valid comment
//this line is safe to be deleted
//this line also is safe to be deleted
//this line also is safe to be deleted