Here is a guide on how to delete your iPod or iPhone backup from your Microsoft computer.
Doing so might save you a bit of hard drive space.
It’s also good to keep things clean if you no longer sync the device with your computer any longer.
Deleting iPad or iPhone via iTunes
Deleting Manually from File Explorer
This method is not as user friendly as deleting them from iTunes as multiple backup’s can not be identified to what device they are.