Thank you for your helpful replies. After analysis, I decided that this was all beyond me, and although I had already consulted Dell several times about this issue, and things only got worse, I tried once more. A sales supervisor at Dell went through and confirmed all your suggestions, but they were all in operation already. So back to the tech people. I turned my computer over to a sweet, knowledgeable young gal in Southern India who took over the computer and spent two hours checking out everything. She finally found a registry error (don't know what that means) and fixed it (something the previous three techs could not really do). Since then every program works correctly. Hooray!
Thanks for all your advice