Transparent marks on my desktop

Ordinarily, my desktop should look something like this:

but now it has some weird transparent window marks on it. No matter how many times i refresh the desktop, it won't disappear... even after rebooting my pc

anyone knows what this is? is it a virus? know how to get rid of it? help would be greatly appreciated.

yeah

change the background

see what programs you have running, they might be causing it

and the obvious one: try rebooting