500gb hdd showing only 40gb free after reinstalling win10

The other day I decided to do a fresh install of windows 10. I got it going and let it run over night. In the morning after entering in all the usual information when I took a look at the Center Drive it was still showing that 460ish gb were still being used even though I told it to not keep any of my files. Is there a way I can fix something like this without wiping the thing a second time?
Thank you!

Try using disk cleanup and remove old windows/installation files.

Yeah there is probably a hidden folder that has the contents of the drive still sitting there. I forget where its kept but if you do use the disk cleanup service it will find the old install and files and purge it all away.