It works. I am duplicating a comment I just made in another post:
Our I.T. folks say that YES they have installed Contenta 4.2 client software successfully on Windows 10. A "few" users are set up this way and are reporting no problems. The one thing I.T. struggled with was opening up the permissions "properly" under the C:\Program Files (x86)\XyEnterprise\Contenta folder. If security on certain child folders is not wide open, files created or written to from the server portal process may fail to write or update, and client-server or client-only tools will all fail.
If your I.T. people are unwilling to do this due to security policy, you may be able to work around this by changing the paths of these target folders (encaps, temp, logs, checkout) in the client's option settings. I tried this once by changing the paths to a place with no security issues, i.e. C:\Users\[username]\Documents\Contenta\...
Now I am talking about Contenta 4.2 with no knowledge of what has changed in 5.0 and later. Also, I am talking about Windows client installs only, not server installation.