Creating an R package is my hobby- a very few number of R programmers or practitioners over the world might claim this but most of them would like to love to document their R code and disseminate their research which is possible only by creating R package because creating R package forces to document own code and provide test examples to ensure that it actually works. This also becomes an ideal way of making sure others have access to own work. This talk is a tutorial of how to create an R package under Windows environment. At the end of the talk, a demonstration with my latest R package called DNAseqtest would be presented as the guideline of gaining confidence for the potential R package builders