Change your code to support virtual folders rather than hard-coded paths. So use "~/logs" to represent the "logs" folder in the root of your site rather than "d:\myprojects\logs" and you can map that value to a folder using
string logFolder = Server.MapPath("~/logs")
That way it will work no matter what server you put it on as MapPath will work out the absolute folder path for you. You're probably better storing this folder in App_Data as well so "~/App_Data/logs"