Weird red line on the left side of the desktop

Okay, my friend told me she has red line on the left side of the screen. First i thought its due to monitor problem but then she sent me screenshot and then i saw the line is behind the icons :S.
It is only on the background but on any wallpaper i change...



Anyone knows how do i get rid of this one?
Thanks

Q: Is it a broken monitor? Or a broken computer? You need to find out. Try this monitor on another computer.

Well its my friends pc, and she dont have another one to try. Can it be due to the monitor because it's only showing on the background wallpaper and it's behind icons?...

if it's the monitor, would not the issue be present always, i.e. always visible regardless of what is displayed/running?

It's not always visible - example when the window is opened and put on that place the line is behind the window...