Right now the space on the C drive is filling up by itself: Virus?

Question

Windows

There were about 3.8 GB of ~ 70 GB left. And then suddenly "Not enough space." I only had a browser open and Visual Studio. I couldn't do it myself. I did not work with the file system. Didn't download anything. There the remainder changed suspiciously though. That 24 MB then 159 MB now shows 139 MB. Where to look, what to do?

Answer 1

There were about 3.8 GB of ~ 70 GB left.

Are you serious about 3.8GB of free space on your system drive?
For normal work - well, there themes to save at least 30-40GB should be free.

I only had a browser open and Visual Studio.

And you also managed to launch the studio with such an amount of free space.

Answer 2

1) Updates
2) Cache / temporary files
3) Swap file
4) Logs (unlikely, but they can)
5) Background programs

Answer 3

shadow copies, to the above

Answer 4

Win+R / Cleanmgr

Answer 5

Transfer all installation caches ( C:\MSOCache, C:\Windows\Installeretc.) to D, and symlink to C.
For example, the folder D:\-disc Cis larger than 20GiB:

MSOCache C:\
Packages C:\ProgramData
"Package Cache" C:\ProgramData
Installer C:\Windows