Hard drive issues / C: drive problems

I’m definitely not some tech wizard or anything, so I figured I’d just throw this out here and see if anyone can help me out...
My C drive is basically screaming at me because it’s completely full; I’ve only got about 10 GB of breathing room left. Does anyone know how I can expand that partition? I’m trying to install a new program and I've hit a wall because there's just no space left to work with...

If you’d actually taken a second to scroll back through the archives, you would’ve stumbled onto this too...