How to know system information

Question

In below code i want to know harddrive information for multiple system which is username and passsword i store in appsettings in app.config file with the help of namevaluecollection i get all keys what is store with below code i want to know whatever username and passowrd i store in appsettings their hardware information .I trying with below code it seems get only local pc drive info .what should i do to get storing appsetiings username and pasword info help? Thnks