The Linux Enpass client has a three pane view with the menu options available horizontally across the top of the app, and the left panel displays the Categories, Tags, and Audit information. The Windows client has the menu options running vertically, and the same panel that's visible on the left side of the Linux client, is collapsed in the Windows client and must be opened to look at the categories, etc.

How can I make the Windows client layout be identical to the Linux client 3 pane layout?

TIA..

I don't have an answer for you, but I have noticed this also, on one machine only. It seems to have something to do with screen resolution. On a Windows 10 machine with 1024x768 resolution, I get the collapsed layout you describe. On that same machine when running Linux at the same resolution, and on all other Windows machines on which I've used Enpass, I get the 3-panel layout.