Hey there, Conhead01!
I'd recommend you to run the Windows Directory Statistics utility and check what is taking up so much space on your drive.
Afterwards, you should be able to run a cleaning tool and restore the free space. I'd also strongly recommend you to run a anti-virus/malware software to check if there is any infection you should be concerned about as well.
Good luck! Hope this helps you!

SuperSoph_WD