Windows 10 pixel, line and face problems.

favorite

I’m a newbie both to here and to blender. I have a problem in so much as since Windows 10 auto installed yesterday I am now unable to work on my current project.
Problem is: I am unable to select either vertices, faces or edges when in edit mode as usual. Works normally if using box select.
If anyone can help it will be appreciated. I’m 82 and self taught, so not too complicated an answer would be great.