After shutting Nas down, when i next start it up, it acts as if it's the first time and asks me to install DSM again?

[hmmark1984]

Sorry if this is a dumb question,

I'm running this from a USB stick in my DIY NAS, the install went great, super easy. I then shutdown the NAS and after a couple of days my new HDDs turned up, so i installed everything and turned the NAS back on, however it went to the first "setting up your new synology device" page, asking me to name it etc....