qBittorrent official forums

when idle, it eats up RAM and starts doing something to the disk
When loading it also tends to take up all available RAM

qbittorent 4.4.0 (64 bit)
Windows 7 Pro SP1 + 16 Гб RAM
Qt:: 5.15.2
Libtorrent:: 2.0.5.0

Honestly, on such an old OS, I'd probably just run some old uTorrent version. 1.6.1 for example or 2.2.1.
qBittorrent is best if it's up-to-date. But Win 7 support has been dropped a while ago, since Win 7 is end-of-life.

I'd probably switch to Windows 10 LTSC, or Windows 10 IoT. These editions feature a very bare-bone OS and they will have updates for many years. Regular Windows 10 is also close to end-of-life. But, none of these editions are easy to get though. They are not really sold for the average Joe.

Or you can also just run Linux, like Manjaro. Unless you game. You can game on Linux, but it's not always the easiest. Anti-cheat is a different story, only a few are compatible.

Good luck.

Thank you, otherwise I’m tired of his strange behavior.

You can go into Settings -> Advanced and set a hard RAM limit.

The issue of qBittorrent consuming RAM even when idle might be due to a memory leak or improper settings. Try updating to the latest version or adjusting settings in qBittorrent.I found a helpful website for student assignment assistance. It's a great websites for assignments to meet your deadlines and get your work done. You can hire a writer from this website if you struggle with writing, whether it's for school or work. It's a simple way to avoid stress and ensure you receive well-written content. This service can make your academic or professional life a lot easier by providing expert support when you need it the most.