I was able to fix the problem of my Nvidia graphics card driver and using an external monitor, thanks to Generix. However, I am now getting a blurred screen on both the external monitor and the laptop, but only when I have the HDMI cord connected. When I move the mouse, the blurriness corrects itself for less than a minute. At other times I get black blocks behind the main programs I am running. I believe the problem may be with the driver for the external monitor ( NEC AccuSync LCD 22 WMGX). I went to the NEC main site and I need to download and install a .exe file, considering Windows OS the only one supported.
I researched online and thought I found a few possible results, but to no avail. Please advise. Thank you.