in two ways you can use WhatsApp on desktop/pc, first by using WhatsApp via its official web.whatsapp.com website, and second by downloading bluestacks into your PC/Desktop and install WhatsApp into pc via bluestacks like you did in Android Phone. otherwise if you want to use dual WhatsApp or if you even any kind of issue in using WhatsApp on PC then I suggest you to download this og whatsapp which also help you to solve this issue.