When I turned on my PC the other day, I got a black screen that said Your Physical Memory has been decreased, press any key to continue.  I was then able to boot up, but received a Dell Warning Event Notification that said

"The amount of physical memory in your system has either been increased or decreased.  This typically does NOT indicate a hardware failure.  Contact your Help Desk if you did not personally change your system's physical memory configuration."

I have not done any memory changes.  I performed a virus scan, clean diskup, and defrag and still receive this message each time I boot up.  I cannot afford any down time so want to fix this before it becomes a problem.  Can anyone help?

Thank you!