Photoshop error installing CS5 Suite

I installed CS5 Design Premium to a new Surface Book 2. Now Photoshop opens full screen, but everything is about 1/4 the size of "normal". When I click on it, the opening ico is also much smaller. The text is so tiny I need a magnifying glass to read it. The other applications all are normal size. Adobe gave me a new download of the software, but that didn't solve the problem.