I've been using PS CS5 since it came out (and loads of previous versions,in their times) on the latest version of Windows. I have a fairly simple workspace that I like and that has given me no problems for a few years. But for the last half-year or so, every time I open PS, the LAYERS set of tabs and the ADJUSTMENTS set of tabs start out collapsed; I have to go to WINDOWS, then WORKSPACE, and then RESET KEN'S WORKSPACE to get to where I need to be. What got messed up? Can this be corrected, so that I don't have to go through this series of clicks?
And here's another question on something that never worked quite right for me: I use the RULER tool much more frequently than the EYEDROPPER tool. I'd like the RULER tool to be the default button on my toolbar, rather than the EYEDROPPER tool, but every time I start PS, the EYEDROPPER is waiting for me. How can I make my preference stick?
tabs start out collapsed
That's a funny coincidence! Ten minutes before I closed down for Easter holiday, my work machine did exactly that. All panels open collapsed. That's CC2018 BTW, not CS5, but maybe it's something in the air...
The first thing I intend to do when I get back to the office over the weekend, is to reset Photoshop's preferences. I expect that will fix it.
Hmm... this might be a pain, but have you tried just resetting all of Photoshop's preferences and going from there?