Vista taskbar clock stopped updating Rebna xxx
If you regularly connect your computer to external displays or docks, then your issue could be related to that.In Windows, you can just press the Windows Key P or go to the Control Panel, click on Display and then click on Adjust Resolution or Change Display Settings.
Once you have it open, click on File and then Run New Task or New Task (Run). This will restart the explorer process and hopefully get you back your taskbar.
Hopefully, one of them will work if nothing else has.
Sometimes you will see this issue when coming back from Sleep mode.
If you instead see a new Windows Explorer window popup, that means the process was already running fine.
If none of these options worked for you, there are a couple of rarer issues that can cause the taskbar to disappear.