When you install the Citrix VDA onto a Windows 10 master image the screen saver capability within the image is disabled. This is by design and a long-standing Citrix workaround to re-enable the screen saver is to add a registry key.
The key you need to add is in HKLM\Software\Citrix\Graphics\ and a new dword entry of SetDisplayRequiredMode and set to 0 which is documented HERE.
Re-enabling this feature allows a the session to be locked automatically after a certain period of inactivity.
However within Windows 10 this causes a rather undesirable side effect. This issue seems to persist across all versions of Windows 10 where if you lock the desktop the clock on the lock screen will not update after a minute or two of inactivity.
So for example if you lock your screen at 12:00 and go to lunch when you return an hour and a half later your lock screen clock will show something like 12:01 or 12:02.
My screen shot shows the problem where my ICA session time should be in exact sync with the client time because the client is actually my own virtual lab where the VDA presenting the ICA session is also running on.
The screen will immediately update as soon as you press a key or move the mouse.
Unfortunately Microsoft are currently not making it easy to customise the lock screen within Windows 10 Enterprise and the 3 main choices for removing the lock screen and just being presented with you username and password dialog currently do not work in Windows 10 1709 Enterprise.
For reference the three options are as follows:
1/ Add or change the NoLockScreen DWORD value to 1 in the following registry location HKLM\Software\Policies\Microsoft\Windows\Personalization\
2/ Configure the Group Policy “Do not display the Lock Screen” within \Computer Configuration\Administrative Templates\Control Panel\Personalisation.
3/ Create a scheduled task that resets the HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Authentication\LogonUI\SessionData\AllowLockScreen DWORD value to 0. A scheduled task for this option is required because if you set the option manually within the image once you lock and unlock the desktop the setting reverts to 1.
4/ This is the only option that produces any results although all it does is load the blank screen saver shortly afterwards. It hides the problem rather than fixing it however. Just configure the group policy setting “User Settings\Policies\Administrative Templates\Control Panel\Personalization\Force Specific screen saver” and then set it to scrnsave.scr
Feel free to try those options but some only work for older versions of Windows 10 and none appear to actually fix the time for Windows 10 Enterprise 1709. Heres hoping 1803 makes this a little easier.
Author: Dale Scriven