I'm back from my trip now and have actually found the installation disks for my MS Works Suite. I don't think Microsoft makes the suite anymore, but it includes MS Word, Money, Picture It, and several other well-known MS titles. At the moment my Picture It won't open either, saying that such and such file is missing. Why did CCleaner delete all these essential files? It expressly claims that it won't do this!
Anyway, I'm about to reinstall Works and Picture It. (I'm amazed that Word is OK.) I'll let you know how this goes.