If it really stopped spinning you don't. There is data recovery software you can run but the drive has to be at least working somewhat for it to work. Otherwise you send a drive to a company that can deconstruct it and maybe get your data. Or you live with the loss of data.
You should backup your data daily if it's important and changes day to day. Weekly to monthly if you don't change drive contents very often. I backup to 2 different internal drives and 2 different external drives. I also have things like pictures and documents that can not be replaced backed up to burned media in a safe at a relatives house. You really can't be too careful. You don't want a system failure or a lightning strike or even a house fire to destroy everyting.
@leocloudy, your software must be really magic to be able to recover data from a drive that doesn't spin.
Can you tell us the secret of how it does this?
@pathat30, if your drive doesn't even attempt to spin up, then it most probably has a bad PCB. That is something that you will most probably be able to fix yourself for less than US$50, maybe even for free.
Could you tell us the model number of your HDD? Could you upload a photo of the component side of the PCB?