So recently starting around on January 16, 2015, my hard drive space was starting to decrease. My computer is a Dell Inspirion One 19, and it runs a 64-bit version of Windows 7. I also got the computer around August 2010.
My computer had around 232 GB before the problem started, but it's now down to 200 GB as of now as seen by this image. It kept going down from then on. I used CCleaner, but it gave me back just 5 GB, and it went away after that. I tried to get rid of the problem with Avast, Malwarebytes and TDSSKiller, but they didn't help at all. I'm having a similar problem to what these guys had. I also tried WinDirStat before, but I couldn't seem to find the problem. I can however show you some images of it on my computer if you like.
On January 11, 2015, I brought back my computer to college after winter break, and while on the trip, the computer fell down a bit, but I caught it with my hand before it could hit the floor of the truck, so I don't know if that damaged it or not. But it might not be that since my computer didn't suffer many symptoms you would get from a damaged hard drive.
So what could be the problem?