Since yesterday my computer acts more and more strangely:
When a video is put in fullscreen (either in a browser, like Youtube, or on the desktop, like VLC), it automatically sets back to normal screen after a random period of time;
At some points, it is impossible to right click on items to get contextual menus;
Sometimes, task manager closes automatically after the opening. Sometimes it doesn't;
The start menu is sometimes inaccessible: when I click on it, it opens and closes instantly;
In the cmd shell, the text erase itself after a few characters.
I launched a Avast full-analysis, and a MalwareBytes analysis, and CCleaner - nothing has changed so far. I also tried to do an Avast analysis at launch of the computer, but it aborts instantly.
I'm about to reset the computer after saving all my files - though I'm asking here if anyone would have a less radical solution. I went online to try to find similar behaviors, but there is so many things happening that it is not obvious to know what to look for. Some forum posts link the task manager closing to a worm, some websites talk about the last Windows update that prevents stopping the computer.
I'm using Windows 10 with the last update.
Thanks for your help!