Icon placement on the desktop is saved when you log out or shut down NT. For performance reasons, locations are noted and saved automatically at that time. If you move a desktop icon from one location to another, you can force a save of the layout by clicking the desktop (single left-click) and then pressing F5. You will see the screen rewrite as NT stores the layout. If you make a lot of changes to arrangement of icons and simply powerdown the box instead of logging out or shutting down, upon reboot, your desktop will revert to what it looked like at the last boot. Of course, if you have a habit of powering down without shutdown, sooner or later you will not have a bootable system. If you have the desktop the way you want it and want to prevent icons being moved around (accidently or on purpose), cut and paste the following script into nosaveicons.reg file and run it.
REGEDIT4 BLANK LINE GOES HERE [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer]
" NoSaveSettings"="1" BLANK LINE GOES HERE
See .REG files for background information on .REG files.
In the NT Resource Kit there is a reg file names Layout.Reg which saves and restores the Desktop Icon layout. Useful if you often change the windows resolution.
Gives an in-depth look at the NT/Windows 95/98 system policies. Step-by-step walkthroughs.