blender eating C drive's space?

I’m a beginner who just installed blender yesterday, first on C, then moved to D when I noticed dramatical and dynamic annihilation of my C’s free space, but turns out, the problem still exists though in a different way. I think, and I’m a noob so excuse me, that blender is storing some files, which I can’t find, but windows gets rid of them at every system restart?
I’ve been playing around with some simple forms today and had blender opened in the bg through most of the day, and after rebooting the laptop the difference in C’s capacity was over 500MB (20,4GB to 21GB).
Is that normal? Can I do something about it?

P.S. I just checked C and even though I haven’t opened blender after restarting the system about 15mins ago, it already jumped from 21GB to 20,9GB of free space. It may be a virus, but that would be weirdly coincidental? this laptop is almost two years old and I’ve never before had this situation.

You might want to check for Blender related files in its temp folder:

In addition to that Blender saves cache files to disk (smoke / fluid simulations etc.).
You will usually find those in a “cache” folder next to the corresponding blend file.

You also might want to check your render settings: Did you enable saving buffers etc. to disk?

All the above files can easily add up to a very significant amount of data.

One thing is for sure - if Blender is not running, it is not writing to disk. Paging file maybe? A lot of stuff is going on on any modern computer, it is normal for disk to be used by the OS and software running on it. Spotify uses 6 GB(!) of disk space on the PC I am writing this on for example.
Blender keeps auto-saves in ‘%AppData%…\Local\Temp’ on Windows, i think that’s the most likely thing that uses up space unexpectedly, but that’s quite useful.
If you think there is a problem with Blender’s usage of disk space you should see how it goes with Autodesk’s products.

Is it only 500 MB? I would start worrying if it’s over 15 GB. You could use some sort of disk analyzing tool to find out exactly where the space is going. something like SpaceSniffer.

Thank you for the replies. I have both Temp folder and render settings set to D. I think it may be as MartinZ says, I just didn’t notice it before and blender just bumped those numbers to noticeable amounts. thankfully, I didn’t observe a permanent disc space reduction, just fluctuations, so this may be just a noob getting spooked by sudden discovery of unknown technological shenanigans haha