Many phones don't share the memory card as a drive without some setting changes and as Android phones are a varied lot, I only know to look around and can't guess how your phone differs.

https://www.google.com/search?q=USB+driver+for+my+DooGee+Mobile+Phone&ie=utf-8&oe=utf-8 does find the downloads at various but there appears to be some 6 or more models. As such you can refine the search and check XDA Developers too.

My fix? Install Dropbox and do this the easy way.