WD Pasport 500gb can't initialise drive

So, i have a WD pasport wich was working as a backup drive for a long time, but today i wanted to erase everything and use it to boot in to windows on my mac i have. Then i found that it was not showing up in my drive list so naturaly i checked on disk management becouse mayby something wierd happend, i dont care about the data on it but i want to use the drive. In disk management it is listed as unalocated, so naturaly i went to realocate the drive. Then i found it was also marked as unknown Not initialised, and when i open wd drive utilities it gives the same error. What can i do to use it again? help is apreciated.