(Redirected) Bizarre Problem!

Hi.  I have a Dell screen monitor, model E197FP..  It is quite old, but works perfectly well, apart from one bizarre problem that I have had since updating my computer to Windows 10.

The only way I can describe it is that the screen looks "washed out" on certain pages.  For example, on this page where I am writing this post, I can hardly see the box which encloses the area in which I am typing.  On Google maps, if I am looking at streets in a town, the street names are there, but I cannot see the outline of the streets or roads themselves.  The print itself is not affected, just the images.

I have played around with brightness and contrast controls, none of which has any effect.  BUT, and this is the bizarre bit, if I press the monitor button for auto-adjust, the images come up perfectly clearly, as they should be, but only for a fleeting second!  Once the auto-adjust is completed, things go back to normal. So clearly the screen is capable of giving me the images I want, but I cannot "capture" that auto-adjust position. 

I've checked pretty much everything I can think of.  I did a search of my Windows 10 to see if there was an updated driver I should install, but it said the driver I already have is the best one for this model of Dell monitor.  Does anybody out there have any suggestions?  And if so, please bear in mind I'm not very teccy, so any suggested solutions would have to be in very simple language! 

Thanks in advance for any help that might be offered.