A couple times, I've seen a Windows 7 computer with no free hard drive space and tons of space used in c:\windows\temp. The answer is in this article:
https://www.computerworld.com/article/3112358/microsoft-windows/windows-7-log-file-compression-bug-can-fill-up-your-hard-drive.html
It's some sort of bug in Windows. The fix is:
1) stop the Windows Module Installer service
2) move all the files out of c:\windows\logs\cbs (I typically move them to c:\windows\logs\cbs.old)
3) delete all the files in c:\windows\temp
4) reboot
