I'm running latest version of Windows 10 on my Surface Pro 4 with i7/16GB/512GB.
Of the 475 GB available space on my SSD, I was using roughly 150GB. All of a sudden, for no reason, I'm now down to a few kilobytes of space. Looks like most of the space is used by the Windows folder where the OS is - see below.
I have the built in virus protection on and it's up-to-date and showing no issues. Any ideavwhat would cause this explosion on HD utilization? Especially stuff going into Windows folder?