Taskbar Disappearing when I maximize a Window

[zgernand]

I have tried unlocking and relocking the task bar. Autohide is turned off. I am not in fullscreen mode. This happens when I maximize excel, firefox, chrome, word, etc. Any suggestions?

 

[paul1149]

Some ideas:

Move the taskbar to a different edge of the screen. Reboot. Then move back.
Return the installation to a previous restore point.
Do a SFC /SCANNOW in an elevated CMD window.