This issue rarely occur in window pc, sometime the taskbar not hide when pc in full screen mode for example watching movies in full screen or playing PowerPoint Presentation the task should be hide, so lets see how to fix this problem, this method will work windows 10, windows 8.1 and windows 7.
1. Right click on taskbar select “Task Manager”
2. Find “Windows Explorer” right click on that and select “Restart” wait for few seconds and that’s it.