My mom's machine did that for awhile. The cause was traced to a power bar with a switch. Instead of tapping the power button on the computer she would reach over and switch it off when done.
Dell Intel Core 2 Duo Processor E7500 Computer
Inspirion 545s 00
Windows 7 Home Premium 64-bit
750GB Hard Drive
The icons that I put on my desktop for 3 of the Games shown on the startup menu will not stay on my desktop. I have done "Create a Shortcut" for Hearts, Freecell, and Spider and they will stay until shutting down. When booting up the next day, they're no longer there. These are the only icons that I have this situation with. The others are fine and do stick around for me, which I'm glad.
Is there a trick to getting the games icons to stay put? Is there somewhere I need to change a setting for the icons to be cleaned up like I did in XP? The ones I have there I don't want to go away on me.