Much of your daily use of Windows revolves around the taskbar, the strip at the bottom of the screen that holds the Start button, Start menu and quick-launch icons for your most-used programs. Precisely because the taskbar is so central to daily use, it can be frustrating when it disappears for no apparent reason. This can happen for a number of reasons, but most require only a few clicks of the mouse to fix.
Hide and Seek
If your taskbar has disappeared, move your mouse cursor to the bottom of the screen and wait a few seconds. If the taskbar slides up into view, it's simply in "Auto-hide" mode. To change it, right-click on any blank part of the bar. Choose "Properties" from the menu that pops up and then click the box next to "Auto-hide the taskbar" to remove the checkmark. If you position your mouse at the screen's bottom and it doesn't pop up, but the mouse cursor changes to a two-headed arrow, the taskbar has been resized until it's not viewable. Fix it by clicking and dragging the arrow upwards, until the taskbar regains its normal size.
The taskbar is controlled by the same Windows Explorer program that shows you the files and folders on your system. If Explorer crashes or malfunctions, this can also make your taskbar disappear. Rebooting your system usually brings it back, but that's an inconvenient fix. Instead, hold down your keyboard's Ctrl, Alt and Delete keys. Choose Task Manager from the pop-up menu and scroll down until you see the listing for Windows Explorer among the running tasks. Highlight it and click "End Task." Then click the "File" menu in the same window and choose "Run new task." Type "Explorer.exe" into the box -- without the quotation marks -- and click "OK" to restart Explorer.