The two problems are likely not caused by the same thing. Start the computer up, Restore Active Desktop, then restart the computer. If active Desktop soesn't display this message this time, then it's problem is likely caused by a problem with shutting the computer down properly.
The CD drive, or cable leading to it has likely failed causing your D drive problem. A replacement drive isn't that expensive, and normally comes with a new cable. Often, you can find someone locally who will give you a used CD-Rom drive for free, and might even install it for next to nothing. For just kids playing games, the system shouldn't need a cd/rw drive even if that is what it has now.