Why is Raspbian's GUI acting weird?

Question

linux

On the second day I launched my newly purchased Raspberry PI. The Rasbian graphical shell began to work very strangely. The cursor is not displayed (if automatic login is enabled), windows are not displayed. All running programs automatically open at the top left, just like the console. I tried to increase the memory for graphics, but it did not help.
What could happen to the OS? And how to return everything to its original state.
PS The last time I installed Cheese from the software (well, by the way) ..

Answer 1

Downloading and writing a new operating system to the card will be the fastest.