how can i lock desktop icons in windows 8

I've done that and still have the problem.

Still a Pita after multiple years with ZERO response from ms...

fwiw, if you are experiencing this with a single monitor, I would bet that the monitor is HDMI.

Since many (perhaps all) HDMI monitors do not notify the cable of their resolution when the monitor is powered down, when the monitor is off and the computer on, windows elects to reset the screen resolution to a registry "default" which is different from most HDMI monitors' actual resolution.

I've managed to set those defaults to my monitor's (1080p) resolution and that prevents windows resizing windows, but windows continues to re-arrange desktop icons to my dismay and to the obvious dismay of many others for the same apparent reason.

What a royal pain and obvious that ms doesn't give a damm about user needs.

glad this worked for you, but I've never had anything except "large icons" and "show desktop icons" checked and it still rearranges them whenever it feels like it.

fwiw, here are the registry entries for a 1080p HDMI monitor to prevent windows from automatically changing the screen's resolution when the HDMI monitor is off and cannot be detected by windows. 

Since windows' default values are for a smaller screen, when windows resizes the screen, in addition to windows being resized and moved, if the desktop icons are laid out so that the layout exceeds the default screen size, the icons are automatically rearranged to fit in that default screen resolution.

HKLM\SYSTEM\CurrentControlSet\Control\GraphicsDrivers\Configuration\SIMULATED_...\00

PrimSurfSize.cx = 1920 (dec)

PrimSurfSize.cy = 1040 (dec)

Stride = 10240 (dec)

The "..." in the key represents a long alpha/numeric string that is part of the keyname.  I have no way of knowing if this part of the keyname that changes with machines, but there should be only one "SIMULATED_..." entry.

Since setting the first two values over a year ago, I have had no window size problems and after discovering the "Stride" entry and value, I have had no problems with window and icon positions.

Hope that this information is of value.

Beverly Howard

This worked for me